| <!DOCTYPE html> |
| <html xmlns="http://www.w3.org/1999/xhtml" lang="en"> |
| <head> |
| <meta charset="UTF-8"/> |
| <meta http-equiv="X-UA-Compatible" content="IE=edge"/> |
| <meta name="viewport" content="width=device-width, initial-scale=1.0"/> |
| <meta name="generator" content="Asciidoctor 2.0.23"/> |
| <title>gittutorial-2(7)</title> |
| <link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Open+Sans:300,300italic,400,400italic,600,600italic%7CNoto+Serif:400,400italic,700,700italic%7CDroid+Sans+Mono:400,700"/> |
| <style> |
| /*! Asciidoctor default stylesheet | MIT License | https://asciidoctor.org */ |
| /* Uncomment the following line when using as a custom stylesheet */ |
| /* @import "https://fonts.googleapis.com/css?family=Open+Sans:300,300italic,400,400italic,600,600italic%7CNoto+Serif:400,400italic,700,700italic%7CDroid+Sans+Mono:400,700"; */ |
| html{font-family:sans-serif;-webkit-text-size-adjust:100%} |
| a{background:none} |
| a:focus{outline:thin dotted} |
| a:active,a:hover{outline:0} |
| h1{font-size:2em;margin:.67em 0} |
| b,strong{font-weight:bold} |
| abbr{font-size:.9em} |
| abbr[title]{cursor:help;border-bottom:1px dotted #dddddf;text-decoration:none} |
| dfn{font-style:italic} |
| hr{height:0} |
| mark{background:#ff0;color:#000} |
| code,kbd,pre,samp{font-family:monospace;font-size:1em} |
| pre{white-space:pre-wrap} |
| q{quotes:"\201C" "\201D" "\2018" "\2019"} |
| small{font-size:80%} |
| sub,sup{font-size:75%;line-height:0;position:relative;vertical-align:baseline} |
| sup{top:-.5em} |
| sub{bottom:-.25em} |
| img{border:0} |
| svg:not(:root){overflow:hidden} |
| figure{margin:0} |
| audio,video{display:inline-block} |
| audio:not([controls]){display:none;height:0} |
| fieldset{border:1px solid silver;margin:0 2px;padding:.35em .625em .75em} |
| legend{border:0;padding:0} |
| button,input,select,textarea{font-family:inherit;font-size:100%;margin:0} |
| button,input{line-height:normal} |
| button,select{text-transform:none} |
| button,html input[type=button],input[type=reset],input[type=submit]{-webkit-appearance:button;cursor:pointer} |
| button[disabled],html input[disabled]{cursor:default} |
| input[type=checkbox],input[type=radio]{padding:0} |
| button::-moz-focus-inner,input::-moz-focus-inner{border:0;padding:0} |
| textarea{overflow:auto;vertical-align:top} |
| table{border-collapse:collapse;border-spacing:0} |
| *,::before,::after{box-sizing:border-box} |
| html,body{font-size:100%} |
| body{background:#fff;color:rgba(0,0,0,.8);padding:0;margin:0;font-family:"Noto Serif","DejaVu Serif",serif;line-height:1;position:relative;cursor:auto;-moz-tab-size:4;-o-tab-size:4;tab-size:4;word-wrap:anywhere;-moz-osx-font-smoothing:grayscale;-webkit-font-smoothing:antialiased} |
| a:hover{cursor:pointer} |
| img,object,embed{max-width:100%;height:auto} |
| object,embed{height:100%} |
| img{-ms-interpolation-mode:bicubic} |
| .left{float:left!important} |
| .right{float:right!important} |
| .text-left{text-align:left!important} |
| .text-right{text-align:right!important} |
| .text-center{text-align:center!important} |
| .text-justify{text-align:justify!important} |
| .hide{display:none} |
| img,object,svg{display:inline-block;vertical-align:middle} |
| textarea{height:auto;min-height:50px} |
| select{width:100%} |
| .subheader,.admonitionblock td.content>.title,.audioblock>.title,.exampleblock>.title,.imageblock>.title,.listingblock>.title,.literalblock>.title,.stemblock>.title,.openblock>.title,.paragraph>.title,.quoteblock>.title,table.tableblock>.title,.verseblock>.title,.videoblock>.title,.dlist>.title,.olist>.title,.ulist>.title,.qlist>.title,.hdlist>.title{line-height:1.45;color:#7a2518;font-weight:400;margin-top:0;margin-bottom:.25em} |
| div,dl,dt,dd,ul,ol,li,h1,h2,h3,#toctitle,.sidebarblock>.content>.title,h4,h5,h6,pre,form,p,blockquote,th,td{margin:0;padding:0} |
| a{color:#2156a5;text-decoration:underline;line-height:inherit} |
| a:hover,a:focus{color:#1d4b8f} |
| a img{border:0} |
| p{line-height:1.6;margin-bottom:1.25em;text-rendering:optimizeLegibility} |
| p aside{font-size:.875em;line-height:1.35;font-style:italic} |
| h1,h2,h3,#toctitle,.sidebarblock>.content>.title,h4,h5,h6{font-family:"Open Sans","DejaVu Sans",sans-serif;font-weight:300;font-style:normal;color:#ba3925;text-rendering:optimizeLegibility;margin-top:1em;margin-bottom:.5em;line-height:1.0125em} |
| h1 small,h2 small,h3 small,#toctitle small,.sidebarblock>.content>.title small,h4 small,h5 small,h6 small{font-size:60%;color:#e99b8f;line-height:0} |
| h1{font-size:2.125em} |
| h2{font-size:1.6875em} |
| h3,#toctitle,.sidebarblock>.content>.title{font-size:1.375em} |
| h4,h5{font-size:1.125em} |
| h6{font-size:1em} |
| hr{border:solid #dddddf;border-width:1px 0 0;clear:both;margin:1.25em 0 1.1875em} |
| em,i{font-style:italic;line-height:inherit} |
| strong,b{font-weight:bold;line-height:inherit} |
| small{font-size:60%;line-height:inherit} |
| code{font-family:"Droid Sans Mono","DejaVu Sans Mono",monospace;font-weight:400;color:rgba(0,0,0,.9)} |
| ul,ol,dl{line-height:1.6;margin-bottom:1.25em;list-style-position:outside;font-family:inherit} |
| ul,ol{margin-left:1.5em} |
| ul li ul,ul li ol{margin-left:1.25em;margin-bottom:0} |
| ul.circle{list-style-type:circle} |
| ul.disc{list-style-type:disc} |
| ul.square{list-style-type:square} |
| ul.circle ul:not([class]),ul.disc ul:not([class]),ul.square ul:not([class]){list-style:inherit} |
| ol li ul,ol li ol{margin-left:1.25em;margin-bottom:0} |
| dl dt{margin-bottom:.3125em;font-weight:bold} |
| dl dd{margin-bottom:1.25em} |
| blockquote{margin:0 0 1.25em;padding:.5625em 1.25em 0 1.1875em;border-left:1px solid #ddd} |
| blockquote,blockquote p{line-height:1.6;color:rgba(0,0,0,.85)} |
| @media screen and (min-width:768px){h1,h2,h3,#toctitle,.sidebarblock>.content>.title,h4,h5,h6{line-height:1.2} |
| h1{font-size:2.75em} |
| h2{font-size:2.3125em} |
| h3,#toctitle,.sidebarblock>.content>.title{font-size:1.6875em} |
| h4{font-size:1.4375em}} |
| table{background:#fff;margin-bottom:1.25em;border:1px solid #dedede;word-wrap:normal} |
| table thead,table tfoot{background:#f7f8f7} |
| table thead tr th,table thead tr td,table tfoot tr th,table tfoot tr td{padding:.5em .625em .625em;font-size:inherit;color:rgba(0,0,0,.8);text-align:left} |
| table tr th,table tr td{padding:.5625em .625em;font-size:inherit;color:rgba(0,0,0,.8)} |
| table tr.even,table tr.alt{background:#f8f8f7} |
| table thead tr th,table tfoot tr th,table tbody tr td,table tr td,table tfoot tr td{line-height:1.6} |
| h1,h2,h3,#toctitle,.sidebarblock>.content>.title,h4,h5,h6{line-height:1.2;word-spacing:-.05em} |
| h1 strong,h2 strong,h3 strong,#toctitle strong,.sidebarblock>.content>.title strong,h4 strong,h5 strong,h6 strong{font-weight:400} |
| .center{margin-left:auto;margin-right:auto} |
| .stretch{width:100%} |
| .clearfix::before,.clearfix::after,.float-group::before,.float-group::after{content:" ";display:table} |
| .clearfix::after,.float-group::after{clear:both} |
| :not(pre).nobreak{word-wrap:normal} |
| :not(pre).nowrap{white-space:nowrap} |
| :not(pre).pre-wrap{white-space:pre-wrap} |
| :not(pre):not([class^=L])>code{font-size:.9375em;font-style:normal!important;letter-spacing:0;padding:.1em .5ex;word-spacing:-.15em;background:#f7f7f8;border-radius:4px;line-height:1.45;text-rendering:optimizeSpeed} |
| pre{color:rgba(0,0,0,.9);font-family:"Droid Sans Mono","DejaVu Sans Mono",monospace;line-height:1.45;text-rendering:optimizeSpeed} |
| pre code,pre pre{color:inherit;font-size:inherit;line-height:inherit} |
| pre>code{display:block} |
| pre.nowrap,pre.nowrap pre{white-space:pre;word-wrap:normal} |
| em em{font-style:normal} |
| strong strong{font-weight:400} |
| .keyseq{color:rgba(51,51,51,.8)} |
| kbd{font-family:"Droid Sans Mono","DejaVu Sans Mono",monospace;display:inline-block;color:rgba(0,0,0,.8);font-size:.65em;line-height:1.45;background:#f7f7f7;border:1px solid #ccc;border-radius:3px;box-shadow:0 1px 0 rgba(0,0,0,.2),inset 0 0 0 .1em #fff;margin:0 .15em;padding:.2em .5em;vertical-align:middle;position:relative;top:-.1em;white-space:nowrap} |
| .keyseq kbd:first-child{margin-left:0} |
| .keyseq kbd:last-child{margin-right:0} |
| .menuseq,.menuref{color:#000} |
| .menuseq b:not(.caret),.menuref{font-weight:inherit} |
| .menuseq{word-spacing:-.02em} |
| .menuseq b.caret{font-size:1.25em;line-height:.8} |
| .menuseq i.caret{font-weight:bold;text-align:center;width:.45em} |
| b.button::before,b.button::after{position:relative;top:-1px;font-weight:400} |
| b.button::before{content:"[";padding:0 3px 0 2px} |
| b.button::after{content:"]";padding:0 2px 0 3px} |
| p a>code:hover{color:rgba(0,0,0,.9)} |
| #header,#content,#footnotes,#footer{width:100%;margin:0 auto;max-width:62.5em;*zoom:1;position:relative;padding-left:.9375em;padding-right:.9375em} |
| #header::before,#header::after,#content::before,#content::after,#footnotes::before,#footnotes::after,#footer::before,#footer::after{content:" ";display:table} |
| #header::after,#content::after,#footnotes::after,#footer::after{clear:both} |
| #content{margin-top:1.25em} |
| #content::before{content:none} |
| #header>h1:first-child{color:rgba(0,0,0,.85);margin-top:2.25rem;margin-bottom:0} |
| #header>h1:first-child+#toc{margin-top:8px;border-top:1px solid #dddddf} |
| #header>h1:only-child{border-bottom:1px solid #dddddf;padding-bottom:8px} |
| #header .details{border-bottom:1px solid #dddddf;line-height:1.45;padding-top:.25em;padding-bottom:.25em;padding-left:.25em;color:rgba(0,0,0,.6);display:flex;flex-flow:row wrap} |
| #header .details span:first-child{margin-left:-.125em} |
| #header .details span.email a{color:rgba(0,0,0,.85)} |
| #header .details br{display:none} |
| #header .details br+span::before{content:"\00a0\2013\00a0"} |
| #header .details br+span.author::before{content:"\00a0\22c5\00a0";color:rgba(0,0,0,.85)} |
| #header .details br+span#revremark::before{content:"\00a0|\00a0"} |
| #header #revnumber{text-transform:capitalize} |
| #header #revnumber::after{content:"\00a0"} |
| #content>h1:first-child:not([class]){color:rgba(0,0,0,.85);border-bottom:1px solid #dddddf;padding-bottom:8px;margin-top:0;padding-top:1rem;margin-bottom:1.25rem} |
| #toc{border-bottom:1px solid #e7e7e9;padding-bottom:.5em} |
| #toc>ul{margin-left:.125em} |
| #toc ul.sectlevel0>li>a{font-style:italic} |
| #toc ul.sectlevel0 ul.sectlevel1{margin:.5em 0} |
| #toc ul{font-family:"Open Sans","DejaVu Sans",sans-serif;list-style-type:none} |
| #toc li{line-height:1.3334;margin-top:.3334em} |
| #toc a{text-decoration:none} |
| #toc a:active{text-decoration:underline} |
| #toctitle{color:#7a2518;font-size:1.2em} |
| @media screen and (min-width:768px){#toctitle{font-size:1.375em} |
| body.toc2{padding-left:15em;padding-right:0} |
| body.toc2 #header>h1:nth-last-child(2){border-bottom:1px solid #dddddf;padding-bottom:8px} |
| #toc.toc2{margin-top:0!important;background:#f8f8f7;position:fixed;width:15em;left:0;top:0;border-right:1px solid #e7e7e9;border-top-width:0!important;border-bottom-width:0!important;z-index:1000;padding:1.25em 1em;height:100%;overflow:auto} |
| #toc.toc2 #toctitle{margin-top:0;margin-bottom:.8rem;font-size:1.2em} |
| #toc.toc2>ul{font-size:.9em;margin-bottom:0} |
| #toc.toc2 ul ul{margin-left:0;padding-left:1em} |
| #toc.toc2 ul.sectlevel0 ul.sectlevel1{padding-left:0;margin-top:.5em;margin-bottom:.5em} |
| body.toc2.toc-right{padding-left:0;padding-right:15em} |
| body.toc2.toc-right #toc.toc2{border-right-width:0;border-left:1px solid #e7e7e9;left:auto;right:0}} |
| @media screen and (min-width:1280px){body.toc2{padding-left:20em;padding-right:0} |
| #toc.toc2{width:20em} |
| #toc.toc2 #toctitle{font-size:1.375em} |
| #toc.toc2>ul{font-size:.95em} |
| #toc.toc2 ul ul{padding-left:1.25em} |
| body.toc2.toc-right{padding-left:0;padding-right:20em}} |
| #content #toc{border:1px solid #e0e0dc;margin-bottom:1.25em;padding:1.25em;background:#f8f8f7;border-radius:4px} |
| #content #toc>:first-child{margin-top:0} |
| #content #toc>:last-child{margin-bottom:0} |
| #footer{max-width:none;background:rgba(0,0,0,.8);padding:1.25em} |
| #footer-text{color:hsla(0,0%,100%,.8);line-height:1.44} |
| #content{margin-bottom:.625em} |
| .sect1{padding-bottom:.625em} |
| @media screen and (min-width:768px){#content{margin-bottom:1.25em} |
| .sect1{padding-bottom:1.25em}} |
| .sect1:last-child{padding-bottom:0} |
| .sect1+.sect1{border-top:1px solid #e7e7e9} |
| #content h1>a.anchor,h2>a.anchor,h3>a.anchor,#toctitle>a.anchor,.sidebarblock>.content>.title>a.anchor,h4>a.anchor,h5>a.anchor,h6>a.anchor{position:absolute;z-index:1001;width:1.5ex;margin-left:-1.5ex;display:block;text-decoration:none!important;visibility:hidden;text-align:center;font-weight:400} |
| #content h1>a.anchor::before,h2>a.anchor::before,h3>a.anchor::before,#toctitle>a.anchor::before,.sidebarblock>.content>.title>a.anchor::before,h4>a.anchor::before,h5>a.anchor::before,h6>a.anchor::before{content:"\00A7";font-size:.85em;display:block;padding-top:.1em} |
| #content h1:hover>a.anchor,#content h1>a.anchor:hover,h2:hover>a.anchor,h2>a.anchor:hover,h3:hover>a.anchor,#toctitle:hover>a.anchor,.sidebarblock>.content>.title:hover>a.anchor,h3>a.anchor:hover,#toctitle>a.anchor:hover,.sidebarblock>.content>.title>a.anchor:hover,h4:hover>a.anchor,h4>a.anchor:hover,h5:hover>a.anchor,h5>a.anchor:hover,h6:hover>a.anchor,h6>a.anchor:hover{visibility:visible} |
| #content h1>a.link,h2>a.link,h3>a.link,#toctitle>a.link,.sidebarblock>.content>.title>a.link,h4>a.link,h5>a.link,h6>a.link{color:#ba3925;text-decoration:none} |
| #content h1>a.link:hover,h2>a.link:hover,h3>a.link:hover,#toctitle>a.link:hover,.sidebarblock>.content>.title>a.link:hover,h4>a.link:hover,h5>a.link:hover,h6>a.link:hover{color:#a53221} |
| details,.audioblock,.imageblock,.literalblock,.listingblock,.stemblock,.videoblock{margin-bottom:1.25em} |
| details{margin-left:1.25rem} |
| details>summary{cursor:pointer;display:block;position:relative;line-height:1.6;margin-bottom:.625rem;outline:none;-webkit-tap-highlight-color:transparent} |
| details>summary::-webkit-details-marker{display:none} |
| details>summary::before{content:"";border:solid transparent;border-left:solid;border-width:.3em 0 .3em .5em;position:absolute;top:.5em;left:-1.25rem;transform:translateX(15%)} |
| details[open]>summary::before{border:solid transparent;border-top:solid;border-width:.5em .3em 0;transform:translateY(15%)} |
| details>summary::after{content:"";width:1.25rem;height:1em;position:absolute;top:.3em;left:-1.25rem} |
| .admonitionblock td.content>.title,.audioblock>.title,.exampleblock>.title,.imageblock>.title,.listingblock>.title,.literalblock>.title,.stemblock>.title,.openblock>.title,.paragraph>.title,.quoteblock>.title,table.tableblock>.title,.verseblock>.title,.videoblock>.title,.dlist>.title,.olist>.title,.ulist>.title,.qlist>.title,.hdlist>.title{text-rendering:optimizeLegibility;text-align:left;font-family:"Noto Serif","DejaVu Serif",serif;font-size:1rem;font-style:italic} |
| table.tableblock.fit-content>caption.title{white-space:nowrap;width:0} |
| .paragraph.lead>p,#preamble>.sectionbody>[class=paragraph]:first-of-type p{font-size:1.21875em;line-height:1.6;color:rgba(0,0,0,.85)} |
| .admonitionblock>table{border-collapse:separate;border:0;background:none;width:100%} |
| .admonitionblock>table td.icon{text-align:center;width:80px} |
| .admonitionblock>table td.icon img{max-width:none} |
| .admonitionblock>table td.icon .title{font-weight:bold;font-family:"Open Sans","DejaVu Sans",sans-serif;text-transform:uppercase} |
| .admonitionblock>table td.content{padding-left:1.125em;padding-right:1.25em;border-left:1px solid #dddddf;color:rgba(0,0,0,.6);word-wrap:anywhere} |
| .admonitionblock>table td.content>:last-child>:last-child{margin-bottom:0} |
| .exampleblock>.content{border:1px solid #e6e6e6;margin-bottom:1.25em;padding:1.25em;background:#fff;border-radius:4px} |
| .sidebarblock{border:1px solid #dbdbd6;margin-bottom:1.25em;padding:1.25em;background:#f3f3f2;border-radius:4px} |
| .sidebarblock>.content>.title{color:#7a2518;margin-top:0;text-align:center} |
| .exampleblock>.content>:first-child,.sidebarblock>.content>:first-child{margin-top:0} |
| .exampleblock>.content>:last-child,.exampleblock>.content>:last-child>:last-child,.exampleblock>.content .olist>ol>li:last-child>:last-child,.exampleblock>.content .ulist>ul>li:last-child>:last-child,.exampleblock>.content .qlist>ol>li:last-child>:last-child,.sidebarblock>.content>:last-child,.sidebarblock>.content>:last-child>:last-child,.sidebarblock>.content .olist>ol>li:last-child>:last-child,.sidebarblock>.content .ulist>ul>li:last-child>:last-child,.sidebarblock>.content .qlist>ol>li:last-child>:last-child{margin-bottom:0} |
| .literalblock pre,.listingblock>.content>pre{border-radius:4px;overflow-x:auto;padding:1em;font-size:.8125em} |
| @media screen and (min-width:768px){.literalblock pre,.listingblock>.content>pre{font-size:.90625em}} |
| @media screen and (min-width:1280px){.literalblock pre,.listingblock>.content>pre{font-size:1em}} |
| .literalblock pre,.listingblock>.content>pre:not(.highlight),.listingblock>.content>pre[class=highlight],.listingblock>.content>pre[class^="highlight "]{background:#f7f7f8} |
| .literalblock.output pre{color:#f7f7f8;background:rgba(0,0,0,.9)} |
| .listingblock>.content{position:relative} |
| .listingblock code[data-lang]::before{display:none;content:attr(data-lang);position:absolute;font-size:.75em;top:.425rem;right:.5rem;line-height:1;text-transform:uppercase;color:inherit;opacity:.5} |
| .listingblock:hover code[data-lang]::before{display:block} |
| .listingblock.terminal pre .command::before{content:attr(data-prompt);padding-right:.5em;color:inherit;opacity:.5} |
| .listingblock.terminal pre .command:not([data-prompt])::before{content:"$"} |
| .listingblock pre.highlightjs{padding:0} |
| .listingblock pre.highlightjs>code{padding:1em;border-radius:4px} |
| .listingblock pre.prettyprint{border-width:0} |
| .prettyprint{background:#f7f7f8} |
| pre.prettyprint .linenums{line-height:1.45;margin-left:2em} |
| pre.prettyprint li{background:none;list-style-type:inherit;padding-left:0} |
| pre.prettyprint li code[data-lang]::before{opacity:1} |
| pre.prettyprint li:not(:first-child) code[data-lang]::before{display:none} |
| table.linenotable{border-collapse:separate;border:0;margin-bottom:0;background:none} |
| table.linenotable td[class]{color:inherit;vertical-align:top;padding:0;line-height:inherit;white-space:normal} |
| table.linenotable td.code{padding-left:.75em} |
| table.linenotable td.linenos,pre.pygments .linenos{border-right:1px solid;opacity:.35;padding-right:.5em;-webkit-user-select:none;-moz-user-select:none;-ms-user-select:none;user-select:none} |
| pre.pygments span.linenos{display:inline-block;margin-right:.75em} |
| .quoteblock{margin:0 1em 1.25em 1.5em;display:table} |
| .quoteblock:not(.excerpt)>.title{margin-left:-1.5em;margin-bottom:.75em} |
| .quoteblock blockquote,.quoteblock p{color:rgba(0,0,0,.85);font-size:1.15rem;line-height:1.75;word-spacing:.1em;letter-spacing:0;font-style:italic;text-align:justify} |
| .quoteblock blockquote{margin:0;padding:0;border:0} |
| .quoteblock blockquote::before{content:"\201c";float:left;font-size:2.75em;font-weight:bold;line-height:.6em;margin-left:-.6em;color:#7a2518;text-shadow:0 1px 2px rgba(0,0,0,.1)} |
| .quoteblock blockquote>.paragraph:last-child p{margin-bottom:0} |
| .quoteblock .attribution{margin-top:.75em;margin-right:.5ex;text-align:right} |
| .verseblock{margin:0 1em 1.25em} |
| .verseblock pre{font-family:"Open Sans","DejaVu Sans",sans-serif;font-size:1.15rem;color:rgba(0,0,0,.85);font-weight:300;text-rendering:optimizeLegibility} |
| .verseblock pre strong{font-weight:400} |
| .verseblock .attribution{margin-top:1.25rem;margin-left:.5ex} |
| .quoteblock .attribution,.verseblock .attribution{font-size:.9375em;line-height:1.45;font-style:italic} |
| .quoteblock .attribution br,.verseblock .attribution br{display:none} |
| .quoteblock .attribution cite,.verseblock .attribution cite{display:block;letter-spacing:-.025em;color:rgba(0,0,0,.6)} |
| .quoteblock.abstract blockquote::before,.quoteblock.excerpt blockquote::before,.quoteblock .quoteblock blockquote::before{display:none} |
| .quoteblock.abstract blockquote,.quoteblock.abstract p,.quoteblock.excerpt blockquote,.quoteblock.excerpt p,.quoteblock .quoteblock blockquote,.quoteblock .quoteblock p{line-height:1.6;word-spacing:0} |
| .quoteblock.abstract{margin:0 1em 1.25em;display:block} |
| .quoteblock.abstract>.title{margin:0 0 .375em;font-size:1.15em;text-align:center} |
| .quoteblock.excerpt>blockquote,.quoteblock .quoteblock{padding:0 0 .25em 1em;border-left:.25em solid #dddddf} |
| .quoteblock.excerpt,.quoteblock .quoteblock{margin-left:0} |
| .quoteblock.excerpt blockquote,.quoteblock.excerpt p,.quoteblock .quoteblock blockquote,.quoteblock .quoteblock p{color:inherit;font-size:1.0625rem} |
| .quoteblock.excerpt .attribution,.quoteblock .quoteblock .attribution{color:inherit;font-size:.85rem;text-align:left;margin-right:0} |
| p.tableblock:last-child{margin-bottom:0} |
| td.tableblock>.content{margin-bottom:1.25em;word-wrap:anywhere} |
| td.tableblock>.content>:last-child{margin-bottom:-1.25em} |
| table.tableblock,th.tableblock,td.tableblock{border:0 solid #dedede} |
| table.grid-all>*>tr>*{border-width:1px} |
| table.grid-cols>*>tr>*{border-width:0 1px} |
| table.grid-rows>*>tr>*{border-width:1px 0} |
| table.frame-all{border-width:1px} |
| table.frame-ends{border-width:1px 0} |
| table.frame-sides{border-width:0 1px} |
| table.frame-none>colgroup+*>:first-child>*,table.frame-sides>colgroup+*>:first-child>*{border-top-width:0} |
| table.frame-none>:last-child>:last-child>*,table.frame-sides>:last-child>:last-child>*{border-bottom-width:0} |
| table.frame-none>*>tr>:first-child,table.frame-ends>*>tr>:first-child{border-left-width:0} |
| table.frame-none>*>tr>:last-child,table.frame-ends>*>tr>:last-child{border-right-width:0} |
| table.stripes-all>*>tr,table.stripes-odd>*>tr:nth-of-type(odd),table.stripes-even>*>tr:nth-of-type(even),table.stripes-hover>*>tr:hover{background:#f8f8f7} |
| th.halign-left,td.halign-left{text-align:left} |
| th.halign-right,td.halign-right{text-align:right} |
| th.halign-center,td.halign-center{text-align:center} |
| th.valign-top,td.valign-top{vertical-align:top} |
| th.valign-bottom,td.valign-bottom{vertical-align:bottom} |
| th.valign-middle,td.valign-middle{vertical-align:middle} |
| table thead th,table tfoot th{font-weight:bold} |
| tbody tr th{background:#f7f8f7} |
| tbody tr th,tbody tr th p,tfoot tr th,tfoot tr th p{color:rgba(0,0,0,.8);font-weight:bold} |
| p.tableblock>code:only-child{background:none;padding:0} |
| p.tableblock{font-size:1em} |
| ol{margin-left:1.75em} |
| ul li ol{margin-left:1.5em} |
| dl dd{margin-left:1.125em} |
| dl dd:last-child,dl dd:last-child>:last-child{margin-bottom:0} |
| li p,ul dd,ol dd,.olist .olist,.ulist .ulist,.ulist .olist,.olist .ulist{margin-bottom:.625em} |
| ul.checklist,ul.none,ol.none,ul.no-bullet,ol.no-bullet,ol.unnumbered,ul.unstyled,ol.unstyled{list-style-type:none} |
| ul.no-bullet,ol.no-bullet,ol.unnumbered{margin-left:.625em} |
| ul.unstyled,ol.unstyled{margin-left:0} |
| li>p:empty:only-child::before{content:"";display:inline-block} |
| ul.checklist>li>p:first-child{margin-left:-1em} |
| ul.checklist>li>p:first-child>.fa-square-o:first-child,ul.checklist>li>p:first-child>.fa-check-square-o:first-child{width:1.25em;font-size:.8em;position:relative;bottom:.125em} |
| ul.checklist>li>p:first-child>input[type=checkbox]:first-child{margin-right:.25em} |
| ul.inline{display:flex;flex-flow:row wrap;list-style:none;margin:0 0 .625em -1.25em} |
| ul.inline>li{margin-left:1.25em} |
| .unstyled dl dt{font-weight:400;font-style:normal} |
| ol.arabic{list-style-type:decimal} |
| ol.decimal{list-style-type:decimal-leading-zero} |
| ol.loweralpha{list-style-type:lower-alpha} |
| ol.upperalpha{list-style-type:upper-alpha} |
| ol.lowerroman{list-style-type:lower-roman} |
| ol.upperroman{list-style-type:upper-roman} |
| ol.lowergreek{list-style-type:lower-greek} |
| .hdlist>table,.colist>table{border:0;background:none} |
| .hdlist>table>tbody>tr,.colist>table>tbody>tr{background:none} |
| td.hdlist1,td.hdlist2{vertical-align:top;padding:0 .625em} |
| td.hdlist1{font-weight:bold;padding-bottom:1.25em} |
| td.hdlist2{word-wrap:anywhere} |
| .literalblock+.colist,.listingblock+.colist{margin-top:-.5em} |
| .colist td:not([class]):first-child{padding:.4em .75em 0;line-height:1;vertical-align:top} |
| .colist td:not([class]):first-child img{max-width:none} |
| .colist td:not([class]):last-child{padding:.25em 0} |
| .thumb,.th{line-height:0;display:inline-block;border:4px solid #fff;box-shadow:0 0 0 1px #ddd} |
| .imageblock.left{margin:.25em .625em 1.25em 0} |
| .imageblock.right{margin:.25em 0 1.25em .625em} |
| .imageblock>.title{margin-bottom:0} |
| .imageblock.thumb,.imageblock.th{border-width:6px} |
| .imageblock.thumb>.title,.imageblock.th>.title{padding:0 .125em} |
| .image.left,.image.right{margin-top:.25em;margin-bottom:.25em;display:inline-block;line-height:0} |
| .image.left{margin-right:.625em} |
| .image.right{margin-left:.625em} |
| a.image{text-decoration:none;display:inline-block} |
| a.image object{pointer-events:none} |
| sup.footnote,sup.footnoteref{font-size:.875em;position:static;vertical-align:super} |
| sup.footnote a,sup.footnoteref a{text-decoration:none} |
| sup.footnote a:active,sup.footnoteref a:active,#footnotes .footnote a:first-of-type:active{text-decoration:underline} |
| #footnotes{padding-top:.75em;padding-bottom:.75em;margin-bottom:.625em} |
| #footnotes hr{width:20%;min-width:6.25em;margin:-.25em 0 .75em;border-width:1px 0 0} |
| #footnotes .footnote{padding:0 .375em 0 .225em;line-height:1.3334;font-size:.875em;margin-left:1.2em;margin-bottom:.2em} |
| #footnotes .footnote a:first-of-type{font-weight:bold;text-decoration:none;margin-left:-1.05em} |
| #footnotes .footnote:last-of-type{margin-bottom:0} |
| #content #footnotes{margin-top:-.625em;margin-bottom:0;padding:.75em 0} |
| div.unbreakable{page-break-inside:avoid} |
| .big{font-size:larger} |
| .small{font-size:smaller} |
| .underline{text-decoration:underline} |
| .overline{text-decoration:overline} |
| .line-through{text-decoration:line-through} |
| .aqua{color:#00bfbf} |
| .aqua-background{background:#00fafa} |
| .black{color:#000} |
| .black-background{background:#000} |
| .blue{color:#0000bf} |
| .blue-background{background:#0000fa} |
| .fuchsia{color:#bf00bf} |
| .fuchsia-background{background:#fa00fa} |
| .gray{color:#606060} |
| .gray-background{background:#7d7d7d} |
| .green{color:#006000} |
| .green-background{background:#007d00} |
| .lime{color:#00bf00} |
| .lime-background{background:#00fa00} |
| .maroon{color:#600000} |
| .maroon-background{background:#7d0000} |
| .navy{color:#000060} |
| .navy-background{background:#00007d} |
| .olive{color:#606000} |
| .olive-background{background:#7d7d00} |
| .purple{color:#600060} |
| .purple-background{background:#7d007d} |
| .red{color:#bf0000} |
| .red-background{background:#fa0000} |
| .silver{color:#909090} |
| .silver-background{background:#bcbcbc} |
| .teal{color:#006060} |
| .teal-background{background:#007d7d} |
| .white{color:#bfbfbf} |
| .white-background{background:#fafafa} |
| .yellow{color:#bfbf00} |
| .yellow-background{background:#fafa00} |
| span.icon>.fa{cursor:default} |
| a span.icon>.fa{cursor:inherit} |
| .admonitionblock td.icon [class^="fa icon-"]{font-size:2.5em;text-shadow:1px 1px 2px rgba(0,0,0,.5);cursor:default} |
| .admonitionblock td.icon .icon-note::before{content:"\f05a";color:#19407c} |
| .admonitionblock td.icon .icon-tip::before{content:"\f0eb";text-shadow:1px 1px 2px rgba(155,155,0,.8);color:#111} |
| .admonitionblock td.icon .icon-warning::before{content:"\f071";color:#bf6900} |
| .admonitionblock td.icon .icon-caution::before{content:"\f06d";color:#bf3400} |
| .admonitionblock td.icon .icon-important::before{content:"\f06a";color:#bf0000} |
| .conum[data-value]{display:inline-block;color:#fff!important;background:rgba(0,0,0,.8);border-radius:50%;text-align:center;font-size:.75em;width:1.67em;height:1.67em;line-height:1.67em;font-family:"Open Sans","DejaVu Sans",sans-serif;font-style:normal;font-weight:bold} |
| .conum[data-value] *{color:#fff!important} |
| .conum[data-value]+b{display:none} |
| .conum[data-value]::after{content:attr(data-value)} |
| pre .conum[data-value]{position:relative;top:-.125em} |
| b.conum *{color:inherit!important} |
| .conum:not([data-value]):empty{display:none} |
| dt,th.tableblock,td.content,div.footnote{text-rendering:optimizeLegibility} |
| h1,h2,p,td.content,span.alt,summary{letter-spacing:-.01em} |
| p strong,td.content strong,div.footnote strong{letter-spacing:-.005em} |
| p,blockquote,dt,td.content,td.hdlist1,span.alt,summary{font-size:1.0625rem} |
| p{margin-bottom:1.25rem} |
| .sidebarblock p,.sidebarblock dt,.sidebarblock td.content,p.tableblock{font-size:1em} |
| .exampleblock>.content{background:#fffef7;border-color:#e0e0dc;box-shadow:0 1px 4px #e0e0dc} |
| .print-only{display:none!important} |
| @page{margin:1.25cm .75cm} |
| @media print{*{box-shadow:none!important;text-shadow:none!important} |
| html{font-size:80%} |
| a{color:inherit!important;text-decoration:underline!important} |
| a.bare,a[href^="#"],a[href^="mailto:"]{text-decoration:none!important} |
| a[href^="http:"]:not(.bare)::after,a[href^="https:"]:not(.bare)::after{content:"(" attr(href) ")";display:inline-block;font-size:.875em;padding-left:.25em} |
| abbr[title]{border-bottom:1px dotted} |
| abbr[title]::after{content:" (" attr(title) ")"} |
| pre,blockquote,tr,img,object,svg{page-break-inside:avoid} |
| thead{display:table-header-group} |
| svg{max-width:100%} |
| p,blockquote,dt,td.content{font-size:1em;orphans:3;widows:3} |
| h2,h3,#toctitle,.sidebarblock>.content>.title{page-break-after:avoid} |
| #header,#content,#footnotes,#footer{max-width:none} |
| #toc,.sidebarblock,.exampleblock>.content{background:none!important} |
| #toc{border-bottom:1px solid #dddddf!important;padding-bottom:0!important} |
| body.book #header{text-align:center} |
| body.book #header>h1:first-child{border:0!important;margin:2.5em 0 1em} |
| body.book #header .details{border:0!important;display:block;padding:0!important} |
| body.book #header .details span:first-child{margin-left:0!important} |
| body.book #header .details br{display:block} |
| body.book #header .details br+span::before{content:none!important} |
| body.book #toc{border:0!important;text-align:left!important;padding:0!important;margin:0!important} |
| body.book #toc,body.book #preamble,body.book h1.sect0,body.book .sect1>h2{page-break-before:always} |
| .listingblock code[data-lang]::before{display:block} |
| #footer{padding:0 .9375em} |
| .hide-on-print{display:none!important} |
| .print-only{display:block!important} |
| .hide-for-print{display:none!important} |
| .show-for-print{display:inherit!important}} |
| @media amzn-kf8,print{#header>h1:first-child{margin-top:1.25rem} |
| .sect1{padding:0!important} |
| .sect1+.sect1{border:0} |
| #footer{background:none} |
| #footer-text{color:rgba(0,0,0,.6);font-size:.9em}} |
| @media amzn-kf8{#header,#content,#footnotes,#footer{padding:0}} |
| </style> |
| <style> |
| pre>code { |
| display: inline; |
| } |
| </style> |
| </head> |
| <body class="manpage"> |
| <div id="header"> |
| <h1>gittutorial-2(7) Manual Page</h1> |
| <h2 id="_name">NAME</h2> |
| <div class="sectionbody"> |
| <p>gittutorial-2 - A tutorial introduction to Git: part two</p> |
| </div> |
| </div> |
| <div id="content"> |
| <div class="sect1"> |
| <h2 id="_synopsis">SYNOPSIS</h2> |
| <div class="sectionbody"> |
| <div class="verseblock"> |
| <pre class="content">git *</pre> |
| </div> |
| </div> |
| </div> |
| <div class="sect1"> |
| <h2 id="_description">DESCRIPTION</h2> |
| <div class="sectionbody"> |
| <div class="paragraph"> |
| <p>You should work through <a href="gittutorial.html">gittutorial(7)</a> before reading this tutorial.</p> |
| </div> |
| <div class="paragraph"> |
| <p>The goal of this tutorial is to introduce two fundamental pieces of |
| Git’s architecture—​the object database and the index file—​and to |
| provide the reader with everything necessary to understand the rest |
| of the Git documentation.</p> |
| </div> |
| </div> |
| </div> |
| <div class="sect1"> |
| <h2 id="_the_git_object_database">The Git object database</h2> |
| <div class="sectionbody"> |
| <div class="paragraph"> |
| <p>Let’s start a new project and create a small amount of history:</p> |
| </div> |
| <div class="listingblock"> |
| <div class="content"> |
| <pre>$ mkdir test-project |
| $ cd test-project |
| $ git init |
| Initialized empty Git repository in .git/ |
| $ echo 'hello world' > file.txt |
| $ git add . |
| $ git commit -a -m "initial commit" |
| [master (root-commit) 54196cc] initial commit |
| 1 file changed, 1 insertion(+) |
| create mode 100644 file.txt |
| $ echo 'hello world!' >file.txt |
| $ git commit -a -m "add emphasis" |
| [master c4d59f3] add emphasis |
| 1 file changed, 1 insertion(+), 1 deletion(-)</pre> |
| </div> |
| </div> |
| <div class="paragraph"> |
| <p>What are the 7 digits of hex that Git responded to the commit with?</p> |
| </div> |
| <div class="paragraph"> |
| <p>We saw in part one of the tutorial that commits have names like this. |
| It turns out that every object in the Git history is stored under |
| a 40-digit hex name. That name is the SHA-1 hash of the object’s |
| contents; among other things, this ensures that Git will never store |
| the same data twice (since identical data is given an identical SHA-1 |
| name), and that the contents of a Git object will never change (since |
| that would change the object’s name as well). The 7 char hex strings |
| here are simply the abbreviation of such 40 character long strings. |
| Abbreviations can be used everywhere where the 40 character strings |
| can be used, so long as they are unambiguous.</p> |
| </div> |
| <div class="paragraph"> |
| <p>It is expected that the content of the commit object you created while |
| following the example above generates a different SHA-1 hash than |
| the one shown above because the commit object records the time when |
| it was created and the name of the person performing the commit.</p> |
| </div> |
| <div class="paragraph"> |
| <p>We can ask Git about this particular object with the <code>cat-file</code> |
| command. Don’t copy the 40 hex digits from this example but use those |
| from your own version. Note that you can shorten it to only a few |
| characters to save yourself typing all 40 hex digits:</p> |
| </div> |
| <div class="listingblock"> |
| <div class="content"> |
| <pre>$ git cat-file -t 54196cc2 |
| commit |
| $ git cat-file commit 54196cc2 |
| tree 92b8b694ffb1675e5975148e1121810081dbdffe |
| author J. Bruce Fields <bfields@puzzle.fieldses.org> 1143414668 -0500 |
| committer J. Bruce Fields <bfields@puzzle.fieldses.org> 1143414668 -0500 |
| |
| initial commit</pre> |
| </div> |
| </div> |
| <div class="paragraph"> |
| <p>A tree can refer to one or more "blob" objects, each corresponding to |
| a file. In addition, a tree can also refer to other tree objects, |
| thus creating a directory hierarchy. You can examine the contents of |
| any tree using ls-tree (remember that a long enough initial portion |
| of the SHA-1 will also work):</p> |
| </div> |
| <div class="listingblock"> |
| <div class="content"> |
| <pre>$ git ls-tree 92b8b694 |
| 100644 blob 3b18e512dba79e4c8300dd08aeb37f8e728b8dad file.txt</pre> |
| </div> |
| </div> |
| <div class="paragraph"> |
| <p>Thus we see that this tree has one file in it. The SHA-1 hash is a |
| reference to that file’s data:</p> |
| </div> |
| <div class="listingblock"> |
| <div class="content"> |
| <pre>$ git cat-file -t 3b18e512 |
| blob</pre> |
| </div> |
| </div> |
| <div class="paragraph"> |
| <p>A "blob" is just file data, which we can also examine with cat-file:</p> |
| </div> |
| <div class="listingblock"> |
| <div class="content"> |
| <pre>$ git cat-file blob 3b18e512 |
| hello world</pre> |
| </div> |
| </div> |
| <div class="paragraph"> |
| <p>Note that this is the old file data; so the object that Git named in |
| its response to the initial tree was a tree with a snapshot of the |
| directory state that was recorded by the first commit.</p> |
| </div> |
| <div class="paragraph"> |
| <p>All of these objects are stored under their SHA-1 names inside the Git |
| directory:</p> |
| </div> |
| <div class="listingblock"> |
| <div class="content"> |
| <pre>$ find .git/objects/ |
| .git/objects/ |
| .git/objects/pack |
| .git/objects/info |
| .git/objects/3b |
| .git/objects/3b/18e512dba79e4c8300dd08aeb37f8e728b8dad |
| .git/objects/92 |
| .git/objects/92/b8b694ffb1675e5975148e1121810081dbdffe |
| .git/objects/54 |
| .git/objects/54/196cc2703dc165cbd373a65a4dcf22d50ae7f7 |
| .git/objects/a0 |
| .git/objects/a0/423896973644771497bdc03eb99d5281615b51 |
| .git/objects/d0 |
| .git/objects/d0/492b368b66bdabf2ac1fd8c92b39d3db916e59 |
| .git/objects/c4 |
| .git/objects/c4/d59f390b9cfd4318117afde11d601c1085f241</pre> |
| </div> |
| </div> |
| <div class="paragraph"> |
| <p>and the contents of these files is just the compressed data plus a |
| header identifying their length and their type. The type is either a |
| blob, a tree, a commit, or a tag.</p> |
| </div> |
| <div class="paragraph"> |
| <p>The simplest commit to find is the HEAD commit, which we can find |
| from .git/HEAD:</p> |
| </div> |
| <div class="listingblock"> |
| <div class="content"> |
| <pre>$ cat .git/HEAD |
| ref: refs/heads/master</pre> |
| </div> |
| </div> |
| <div class="paragraph"> |
| <p>As you can see, this tells us which branch we’re currently on, and it |
| tells us this by naming a file under the .git directory, which itself |
| contains a SHA-1 name referring to a commit object, which we can |
| examine with cat-file:</p> |
| </div> |
| <div class="listingblock"> |
| <div class="content"> |
| <pre>$ cat .git/refs/heads/master |
| c4d59f390b9cfd4318117afde11d601c1085f241 |
| $ git cat-file -t c4d59f39 |
| commit |
| $ git cat-file commit c4d59f39 |
| tree d0492b368b66bdabf2ac1fd8c92b39d3db916e59 |
| parent 54196cc2703dc165cbd373a65a4dcf22d50ae7f7 |
| author J. Bruce Fields <bfields@puzzle.fieldses.org> 1143418702 -0500 |
| committer J. Bruce Fields <bfields@puzzle.fieldses.org> 1143418702 -0500 |
| |
| add emphasis</pre> |
| </div> |
| </div> |
| <div class="paragraph"> |
| <p>The "tree" object here refers to the new state of the tree:</p> |
| </div> |
| <div class="listingblock"> |
| <div class="content"> |
| <pre>$ git ls-tree d0492b36 |
| 100644 blob a0423896973644771497bdc03eb99d5281615b51 file.txt |
| $ git cat-file blob a0423896 |
| hello world!</pre> |
| </div> |
| </div> |
| <div class="paragraph"> |
| <p>and the "parent" object refers to the previous commit:</p> |
| </div> |
| <div class="listingblock"> |
| <div class="content"> |
| <pre>$ git cat-file commit 54196cc2 |
| tree 92b8b694ffb1675e5975148e1121810081dbdffe |
| author J. Bruce Fields <bfields@puzzle.fieldses.org> 1143414668 -0500 |
| committer J. Bruce Fields <bfields@puzzle.fieldses.org> 1143414668 -0500 |
| |
| initial commit</pre> |
| </div> |
| </div> |
| <div class="paragraph"> |
| <p>The tree object is the tree we examined first, and this commit is |
| unusual in that it lacks any parent.</p> |
| </div> |
| <div class="paragraph"> |
| <p>Most commits have only one parent, but it is also common for a commit |
| to have multiple parents. In that case the commit represents a |
| merge, with the parent references pointing to the heads of the merged |
| branches.</p> |
| </div> |
| <div class="paragraph"> |
| <p>Besides blobs, trees, and commits, the only remaining type of object |
| is a "tag", which we won’t discuss here; refer to <a href="git-tag.html">git-tag(1)</a> |
| for details.</p> |
| </div> |
| <div class="paragraph"> |
| <p>So now we know how Git uses the object database to represent a |
| project’s history:</p> |
| </div> |
| <div class="ulist"> |
| <ul> |
| <li> |
| <p>"commit" objects refer to "tree" objects representing the |
| snapshot of a directory tree at a particular point in the |
| history, and refer to "parent" commits to show how they’re |
| connected into the project history.</p> |
| </li> |
| <li> |
| <p>"tree" objects represent the state of a single directory, |
| associating directory names to "blob" objects containing file |
| data and "tree" objects containing subdirectory information.</p> |
| </li> |
| <li> |
| <p>"blob" objects contain file data without any other structure.</p> |
| </li> |
| <li> |
| <p>References to commit objects at the head of each branch are |
| stored in files under .git/refs/heads/.</p> |
| </li> |
| <li> |
| <p>The name of the current branch is stored in .git/HEAD.</p> |
| </li> |
| </ul> |
| </div> |
| <div class="paragraph"> |
| <p>Note, by the way, that lots of commands take a tree as an argument. |
| But as we can see above, a tree can be referred to in many different |
| ways—​by the SHA-1 name for that tree, by the name of a commit that |
| refers to the tree, by the name of a branch whose head refers to that |
| tree, etc.--and most such commands can accept any of these names.</p> |
| </div> |
| <div class="paragraph"> |
| <p>In command synopses, the word "tree-ish" is sometimes used to |
| designate such an argument.</p> |
| </div> |
| </div> |
| </div> |
| <div class="sect1"> |
| <h2 id="_the_index_file">The index file</h2> |
| <div class="sectionbody"> |
| <div class="paragraph"> |
| <p>The primary tool we’ve been using to create commits is <code>git-commit</code> |
| <code>-a</code>, which creates a commit including every change you’ve made to |
| your working tree. But what if you want to commit changes only to |
| certain files? Or only certain changes to certain files?</p> |
| </div> |
| <div class="paragraph"> |
| <p>If we look at the way commits are created under the cover, we’ll see |
| that there are more flexible ways creating commits.</p> |
| </div> |
| <div class="paragraph"> |
| <p>Continuing with our test-project, let’s modify file.txt again:</p> |
| </div> |
| <div class="listingblock"> |
| <div class="content"> |
| <pre>$ echo "hello world, again" >>file.txt</pre> |
| </div> |
| </div> |
| <div class="paragraph"> |
| <p>but this time instead of immediately making the commit, let’s take an |
| intermediate step, and ask for diffs along the way to keep track of |
| what’s happening:</p> |
| </div> |
| <div class="listingblock"> |
| <div class="content"> |
| <pre>$ git diff |
| --- a/file.txt |
| +++ b/file.txt |
| @@ -1 +1,2 @@ |
| hello world! |
| +hello world, again |
| $ git add file.txt |
| $ git diff</pre> |
| </div> |
| </div> |
| <div class="paragraph"> |
| <p>The last diff is empty, but no new commits have been made, and the |
| head still doesn’t contain the new line:</p> |
| </div> |
| <div class="listingblock"> |
| <div class="content"> |
| <pre>$ git diff HEAD |
| diff --git a/file.txt b/file.txt |
| index a042389..513feba 100644 |
| --- a/file.txt |
| +++ b/file.txt |
| @@ -1 +1,2 @@ |
| hello world! |
| +hello world, again</pre> |
| </div> |
| </div> |
| <div class="paragraph"> |
| <p>So <em>git diff</em> is comparing against something other than the head. |
| The thing that it’s comparing against is actually the index file, |
| which is stored in .git/index in a binary format, but whose contents |
| we can examine with ls-files:</p> |
| </div> |
| <div class="listingblock"> |
| <div class="content"> |
| <pre>$ git ls-files --stage |
| 100644 513feba2e53ebbd2532419ded848ba19de88ba00 0 file.txt |
| $ git cat-file -t 513feba2 |
| blob |
| $ git cat-file blob 513feba2 |
| hello world! |
| hello world, again</pre> |
| </div> |
| </div> |
| <div class="paragraph"> |
| <p>So what our <em>git add</em> did was store a new blob and then put |
| a reference to it in the index file. If we modify the file again, |
| we’ll see that the new modifications are reflected in the <em>git diff</em> |
| output:</p> |
| </div> |
| <div class="listingblock"> |
| <div class="content"> |
| <pre>$ echo 'again?' >>file.txt |
| $ git diff |
| index 513feba..ba3da7b 100644 |
| --- a/file.txt |
| +++ b/file.txt |
| @@ -1,2 +1,3 @@ |
| hello world! |
| hello world, again |
| +again?</pre> |
| </div> |
| </div> |
| <div class="paragraph"> |
| <p>With the right arguments, <em>git diff</em> can also show us the difference |
| between the working directory and the last commit, or between the |
| index and the last commit:</p> |
| </div> |
| <div class="listingblock"> |
| <div class="content"> |
| <pre>$ git diff HEAD |
| diff --git a/file.txt b/file.txt |
| index a042389..ba3da7b 100644 |
| --- a/file.txt |
| +++ b/file.txt |
| @@ -1 +1,3 @@ |
| hello world! |
| +hello world, again |
| +again? |
| $ git diff --cached |
| diff --git a/file.txt b/file.txt |
| index a042389..513feba 100644 |
| --- a/file.txt |
| +++ b/file.txt |
| @@ -1 +1,2 @@ |
| hello world! |
| +hello world, again</pre> |
| </div> |
| </div> |
| <div class="paragraph"> |
| <p>At any time, we can create a new commit using <em>git commit</em> (without |
| the "-a" option), and verify that the state committed only includes the |
| changes stored in the index file, not the additional change that is |
| still only in our working tree:</p> |
| </div> |
| <div class="listingblock"> |
| <div class="content"> |
| <pre>$ git commit -m "repeat" |
| $ git diff HEAD |
| diff --git a/file.txt b/file.txt |
| index 513feba..ba3da7b 100644 |
| --- a/file.txt |
| +++ b/file.txt |
| @@ -1,2 +1,3 @@ |
| hello world! |
| hello world, again |
| +again?</pre> |
| </div> |
| </div> |
| <div class="paragraph"> |
| <p>So by default <em>git commit</em> uses the index to create the commit, not |
| the working tree; the "-a" option to commit tells it to first update |
| the index with all changes in the working tree.</p> |
| </div> |
| <div class="paragraph"> |
| <p>Finally, it’s worth looking at the effect of <em>git add</em> on the index |
| file:</p> |
| </div> |
| <div class="listingblock"> |
| <div class="content"> |
| <pre>$ echo "goodbye, world" >closing.txt |
| $ git add closing.txt</pre> |
| </div> |
| </div> |
| <div class="paragraph"> |
| <p>The effect of the <em>git add</em> was to add one entry to the index file:</p> |
| </div> |
| <div class="listingblock"> |
| <div class="content"> |
| <pre>$ git ls-files --stage |
| 100644 8b9743b20d4b15be3955fc8d5cd2b09cd2336138 0 closing.txt |
| 100644 513feba2e53ebbd2532419ded848ba19de88ba00 0 file.txt</pre> |
| </div> |
| </div> |
| <div class="paragraph"> |
| <p>And, as you can see with cat-file, this new entry refers to the |
| current contents of the file:</p> |
| </div> |
| <div class="listingblock"> |
| <div class="content"> |
| <pre>$ git cat-file blob 8b9743b2 |
| goodbye, world</pre> |
| </div> |
| </div> |
| <div class="paragraph"> |
| <p>The "status" command is a useful way to get a quick summary of the |
| situation:</p> |
| </div> |
| <div class="listingblock"> |
| <div class="content"> |
| <pre>$ git status |
| On branch master |
| Changes to be committed: |
| (use "git restore --staged <file>..." to unstage) |
| |
| new file: closing.txt |
| |
| Changes not staged for commit: |
| (use "git add <file>..." to update what will be committed) |
| (use "git restore <file>..." to discard changes in working directory) |
| |
| modified: file.txt</pre> |
| </div> |
| </div> |
| <div class="paragraph"> |
| <p>Since the current state of closing.txt is cached in the index file, |
| it is listed as "Changes to be committed". Since file.txt has |
| changes in the working directory that aren’t reflected in the index, |
| it is marked "changed but not updated". At this point, running "git |
| commit" would create a commit that added closing.txt (with its new |
| contents), but that didn’t modify file.txt.</p> |
| </div> |
| <div class="paragraph"> |
| <p>Also, note that a bare <code>git</code> <code>diff</code> shows the changes to file.txt, but |
| not the addition of closing.txt, because the version of closing.txt |
| in the index file is identical to the one in the working directory.</p> |
| </div> |
| <div class="paragraph"> |
| <p>In addition to being the staging area for new commits, the index file |
| is also populated from the object database when checking out a |
| branch, and is used to hold the trees involved in a merge operation. |
| See <a href="gitcore-tutorial.html">gitcore-tutorial(7)</a> and the relevant man |
| pages for details.</p> |
| </div> |
| </div> |
| </div> |
| <div class="sect1"> |
| <h2 id="_what_next">What next?</h2> |
| <div class="sectionbody"> |
| <div class="paragraph"> |
| <p>At this point you should know everything necessary to read the man |
| pages for any of the git commands; one good place to start would be |
| with the commands mentioned in <a href="giteveryday.html">giteveryday(7)</a>. You |
| should be able to find any unknown jargon in <a href="gitglossary.html">gitglossary(7)</a>.</p> |
| </div> |
| <div class="paragraph"> |
| <p>The <a href="user-manual.html">Git User’s Manual</a> provides a more |
| comprehensive introduction to Git.</p> |
| </div> |
| <div class="paragraph"> |
| <p><a href="gitcvs-migration.html">gitcvs-migration(7)</a> explains how to |
| import a CVS repository into Git, and shows how to use Git in a |
| CVS-like way.</p> |
| </div> |
| <div class="paragraph"> |
| <p>For some interesting examples of Git use, see the |
| <a href="howto-index.html">howtos</a>.</p> |
| </div> |
| <div class="paragraph"> |
| <p>For Git developers, <a href="gitcore-tutorial.html">gitcore-tutorial(7)</a> goes |
| into detail on the lower-level Git mechanisms involved in, for |
| example, creating a new commit.</p> |
| </div> |
| </div> |
| </div> |
| <div class="sect1"> |
| <h2 id="_see_also">SEE ALSO</h2> |
| <div class="sectionbody"> |
| <div class="paragraph"> |
| <p><a href="gittutorial.html">gittutorial(7)</a>, |
| <a href="gitcvs-migration.html">gitcvs-migration(7)</a>, |
| <a href="gitcore-tutorial.html">gitcore-tutorial(7)</a>, |
| <a href="gitglossary.html">gitglossary(7)</a>, |
| <a href="git-help.html">git-help(1)</a>, |
| <a href="giteveryday.html">giteveryday(7)</a>, |
| <a href="user-manual.html">The Git User’s Manual</a></p> |
| </div> |
| </div> |
| </div> |
| <div class="sect1"> |
| <h2 id="_git">GIT</h2> |
| <div class="sectionbody"> |
| <div class="paragraph"> |
| <p>Part of the <a href="git.html">git(1)</a> suite</p> |
| </div> |
| </div> |
| </div> |
| </div> |
| <div id="footer"> |
| <div id="footer-text"> |
| Last updated 2025-02-14 21:38:14 -0800 |
| </div> |
| </div> |
| </body> |
| </html> |
