STRVERSCMP(3) Linux Programmer's Manual STRVERSCMP(3)
strverscmp - compare two version strings
int strverscmp(const char *s1, const char *s2);
Often one has files jan1, jan2, ..., jan9, jan10, ... and it feels wrong when ls 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 only finds 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
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 containing (or starting at, or ending at) this position. If one or both of these
is empty, then return what strcmp would have returned (numerical ordering of byte values).
Otherwise, compare both digit strings numerically, where digit strings with one or more
leading zeroes are interpreted as if they have a decimal point in front (so that in par-
ticular digit strings with more leading zeroes come before digit strings with fewer lead-
ing zeroes). Thus, the ordering is 000, 00, 01, 010, 09, 0, 1, 9, 10.
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.
This function is a GNU extension.
rename(1), strcasecmp(3), strcmp(3), strcoll(3)
GNU 2001-12-19 STRVERSCMP(3)