| .\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk) |
| .\" |
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| .\" permission notice identical to this one. |
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| .\" Since the Linux kernel and libraries are constantly changing, this |
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| .\" References consulted: |
| .\" Linux libc source code |
| .\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) |
| .\" 386BSD man pages |
| .\" Modified Sat Jul 24 19:23:25 1993 by Rik Faith (faith@cs.unc.edu) |
| .\" Modified Mon May 27 21:37:47 1996 by Martin Schulze (joey@linux.de) |
| .\" |
| .TH GETPW 3 2021-03-22 "GNU" "Linux Programmer's Manual" |
| .SH NAME |
| getpw \- reconstruct password line entry |
| .SH SYNOPSIS |
| .nf |
| .BR "#define _GNU_SOURCE" " /* See feature_test_macros(7) */" |
| .B #include <sys/types.h> |
| .B #include <pwd.h> |
| .PP |
| .BI "int getpw(uid_t " uid ", char *" buf ); |
| .fi |
| .SH DESCRIPTION |
| The |
| .BR getpw () |
| function reconstructs the password line entry for |
| the given user ID \fIuid\fP in the buffer \fIbuf\fP. |
| The returned buffer contains a line of format |
| .PP |
| .in +4n |
| .EX |
| .B name:passwd:uid:gid:gecos:dir:shell |
| .EE |
| .in |
| .PP |
| The \fIpasswd\fP structure is defined in \fI<pwd.h>\fP as follows: |
| .PP |
| .in +4n |
| .EX |
| struct passwd { |
| char *pw_name; /* username */ |
| char *pw_passwd; /* user password */ |
| uid_t pw_uid; /* user ID */ |
| gid_t pw_gid; /* group ID */ |
| char *pw_gecos; /* user information */ |
| char *pw_dir; /* home directory */ |
| char *pw_shell; /* shell program */ |
| }; |
| .EE |
| .in |
| .PP |
| For more information about the fields of this structure, see |
| .BR passwd (5). |
| .SH RETURN VALUE |
| The |
| .BR getpw () |
| function returns 0 on success; on error, it returns \-1, and |
| .I errno |
| is set to indicate the error. |
| .PP |
| If |
| .I uid |
| is not found in the password database, |
| .BR getpw () |
| returns \-1, sets |
| .I errno |
| to 0, and leaves |
| .I buf |
| unchanged. |
| .SH ERRORS |
| .TP |
| .BR 0 " or " ENOENT |
| No user corresponding to |
| .IR uid . |
| .TP |
| .B EINVAL |
| .I buf |
| is NULL. |
| .TP |
| .B ENOMEM |
| Insufficient memory to allocate |
| .I passwd |
| structure. |
| .SH FILES |
| .TP |
| .I /etc/passwd |
| password database file |
| .SH ATTRIBUTES |
| For an explanation of the terms used in this section, see |
| .BR attributes (7). |
| .ad l |
| .nh |
| .TS |
| allbox; |
| lbx lb lb |
| l l l. |
| Interface Attribute Value |
| T{ |
| .BR getpw () |
| T} Thread safety MT-Safe locale |
| .TE |
| .hy |
| .ad |
| .sp 1 |
| .SH CONFORMING TO |
| SVr2. |
| .SH BUGS |
| The |
| .BR getpw () |
| function is dangerous as it may overflow the provided buffer |
| .IR buf . |
| It is obsoleted by |
| .BR getpwuid (3). |
| .SH SEE ALSO |
| .BR endpwent (3), |
| .BR fgetpwent (3), |
| .BR getpwent (3), |
| .BR getpwnam (3), |
| .BR getpwuid (3), |
| .BR putpwent (3), |
| .BR setpwent (3), |
| .BR passwd (5) |
