| .\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk) |
| .\" |
| .\" %%%LICENSE_START(VERBATIM) |
| .\" Permission is granted to make and distribute verbatim copies of this |
| .\" manual provided the copyright notice and this permission notice are |
| .\" preserved on all copies. |
| .\" |
| .\" Permission is granted to copy and distribute modified versions of this |
| .\" manual under the conditions for verbatim copying, provided that the |
| .\" entire resulting derived work is distributed under the terms of a |
| .\" permission notice identical to this one. |
| .\" |
| .\" Since the Linux kernel and libraries are constantly changing, this |
| .\" manual page may be incorrect or out-of-date. The author(s) assume no |
| .\" responsibility for errors or omissions, or for damages resulting from |
| .\" the use of the information contained herein. The author(s) may not |
| .\" have taken the same level of care in the production of this manual, |
| .\" which is licensed free of charge, as they might when working |
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| .\" Formatted or processed versions of this manual, if unaccompanied by |
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| .\" %%%LICENSE_END |
| .\" |
| .\" References consulted: |
| .\" Linux libc source code |
| .\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) |
| .\" 386BSD man pages |
| .\" Modified Sat Jul 24 17:56:43 1993 by Rik Faith (faith@cs.unc.edu) |
| .\" Added history, aeb, 980113. |
| .\" 2005-05-05 mtk: added strcasestr() |
| .\" |
| .TH STRSTR 3 2021-03-22 "GNU" "Linux Programmer's Manual" |
| .SH NAME |
| strstr, strcasestr \- locate a substring |
| .SH SYNOPSIS |
| .nf |
| .B #include <string.h> |
| .PP |
| .BI "char *strstr(const char *" haystack ", const char *" needle ); |
| .PP |
| .BR "#define _GNU_SOURCE" " /* See feature_test_macros(7) */" |
| .B #include <string.h> |
| .PP |
| .BI "char *strcasestr(const char *" haystack ", const char *" needle ); |
| .fi |
| .SH DESCRIPTION |
| The |
| .BR strstr () |
| function finds the first occurrence of the substring |
| .I needle |
| in the string |
| .IR haystack . |
| The terminating null bytes (\(aq\e0\(aq) are not compared. |
| .PP |
| The |
| .BR strcasestr () |
| function is like |
| .BR strstr (), |
| but ignores the case of both arguments. |
| .SH RETURN VALUE |
| These functions return a pointer to the beginning of the |
| located substring, or NULL if the substring is not found. |
| .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 strstr () |
| T} Thread safety MT-Safe |
| T{ |
| .BR strcasestr () |
| T} Thread safety MT-Safe locale |
| .TE |
| .hy |
| .ad |
| .sp 1 |
| .SH CONFORMING TO |
| .BR strstr (): |
| POSIX.1-2001, POSIX.1-2008, C89, C99. |
| .PP |
| The |
| .BR strcasestr () |
| function is a nonstandard extension. |
| .SH SEE ALSO |
| .BR index (3), |
| .BR memchr (3), |
| .BR memmem (3), |
| .BR rindex (3), |
| .BR strcasecmp (3), |
| .BR strchr (3), |
| .BR string (3), |
| .BR strpbrk (3), |
| .BR strsep (3), |
| .BR strspn (3), |
| .BR strtok (3), |
| .BR wcsstr (3) |
