| strcasecmp(3) | Library Functions Manual | strcasecmp(3) |
NAME¶
strcasecmp - strings case-insensitive compare
LIBRARY¶
Standard C library (libc, -lc)
SYNOPSIS¶
#include <strings.h>
int strcasecmp(const char *s1, const char *s2);
DESCRIPTION¶
The strcasecmp() function performs a byte-by-byte comparison of the strings s1 and s2, ignoring the case of the characters. It returns an integer less than, equal to, or greater than zero if s1 is found, respectively, to be less than, to match, or be greater than s2.
RETURN VALUE¶
The strcasecmp() function returns an integer less than, equal to, or greater than zero if s1 is, after ignoring case, found to be less than, to match, or be greater than s2, respectively.
ATTRIBUTES¶
For an explanation of the terms used in this section, see attributes(7).
| Interface | Attribute | Value |
| strcasecmp () | Thread safety | MT-Safe locale |
STANDARDS¶
POSIX.1-2008.
HISTORY¶
4.4BSD, POSIX.1-2001.
strcasecmp() first appeared in 4.4BSD, where it was declared in <string.h>. Thus, for reasons of historical compatibility, the glibc <string.h> header file also declares this function, if the _DEFAULT_SOURCE (or, in glibc 2.19 and earlier, _BSD_SOURCE) feature test macro is defined.
The POSIX.1-2008 standard says of this function:
SEE ALSO¶
| 2026-08-10 | Linux man-pages (unreleased) |