Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

Man Page or Keyword Search:
Man Architecture
Apropos Keyword Search (all sections) Output format
home | help
STRVERSCMP(3)		   Linux Programmer's Manual		 STRVERSCMP(3)

NAME
       strverscmp - compare two	version	strings

SYNOPSIS
       #define _GNU_SOURCE	   /* See feature_test_macros(7) */
       #include	<string.h>

       int strverscmp(const char *s1, const char *s2);

DESCRIPTION
       Often  one  has	files  jan1, jan2, ...,	jan9, jan10, ...  and it feels
       wrong when ls(1)	orders them jan1, jan10, ...,  jan2,  ...,  jan9.   In
       order  to rectify this, GNU introduced the -v option to ls(1), which is
       implemented using versionsort(3), which again uses strverscmp().

       Thus, the task of strverscmp() is to compare two	strings	and  find  the
       "right"	order,	while  strcmp(3)  finds	 only the lexicographic	order.
       This function does not use the locale category LC_COLLATE, so is	 meant
       mostly for situations where the strings are expected to be in ASCII.

       What  this  function does is the	following.  If both strings are	equal,
       return 0.  Otherwise, find the position	between	 two  bytes  with  the
       property	that before it both strings are	equal, while directly after it
       there is	a difference.  Find the	largest	consecutive digit strings con-
       taining	(or  starting at, or ending at)	this position.	If one or both
       of these	is empty, then	return	what  strcmp(3)	 would	have  returned
       (numerical  ordering  of	 byte  values).	 Otherwise, compare both digit
       strings numerically, where digit	strings	with one or more leading zeros
       are  interpreted	 as  if	they have a decimal point in front (so that in
       particular digit	strings	with more  leading  zeros  come	 before	 digit
       strings	with fewer leading zeros).  Thus, the ordering is 000, 00, 01,
       010, 09,	0, 1, 9, 10.

RETURN VALUE
       The strverscmp()	function returns an integer less than,	equal  to,  or
       greater	than  zero  if	s1 is found, respectively, to be earlier than,
       equal to, or later than s2.

CONFORMING TO
       This function is	a GNU extension.

SEE ALSO
       rename(1), strcasecmp(3), strcmp(3), strcoll(3)

COLOPHON
       This page is part of release 3.74 of the	Linux  man-pages  project.   A
       description  of	the project, information about reporting bugs, and the
       latest	 version    of	  this	  page,	   can	   be	  found	    at
       http://www.kernel.org/doc/man-pages/.

GNU				  2001-12-19			 STRVERSCMP(3)

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | CONFORMING TO | SEE ALSO | COLOPHON

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=strverscmp&manpath=Debian+8.1.0>

home | help