Man Versionsort en anglais
SCANDIR(3) Linux Programmer's Manual SCANDIR(3)
NAME
scandir, alphasort, versionsort - scan a directory for matching entries
SYNOPSIS
#include
int scandir(const char *dir, struct dirent ***namelist,
int (*filter)(const struct dirent *),
int (*compar)(const struct dirent **, const struct dirent **));
int alphasort(const void *a, const void *b);
int versionsort(const void *a, const void *b);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
scandir(), alphasort(): _BSD_SOURCE || _SVID_SOURCE
versionsort(): _GNU_SOURCE
DESCRIPTION
The scandir() function scans the directory dir, calling filter() on
each directory entry. Entries for which filter() returns non-zero are
stored in strings allocated via malloc(3), sorted using qsort(3) with
the comparison function compar(), and collected in array namelist which
is allocated via malloc(3). If filter is NULL, all entries are
selected.
The alphasort() and versionsort() functions can be used as the compari-
son function compar(). The former sorts directory entries using str-
coll(3), the latter using strverscmp(3) on the strings (*a)->d_name and
(*b)->d_name.
RETURN VALUE
The scandir() function returns the number of directory entries selected
or -1 if an error occurs.
The alphasort() and versionsort() functions return an integer less
than, equal to, or greater than zero if the first argument is consid-
ered to be respectively less than, equal to, or greater than the sec-
ond.
ERRORS
ENOMEM Insufficient memory to complete the operation.
CONFORMING TO
None of these functions is in POSIX.1-2001, but alphasort() and scan-
dir() are under consideration for a future revision to POSIX.1.
The functions scandir() and alphasort() are from 4.3BSD, and have been
available under Linux since libc4. Libc4 and libc5 use the more pre-
cise prototype
int alphasort(const struct dirent ** a,
const struct dirent **b);
but glibc 2.0 returns to the imprecise BSD prototype.
The function versionsort() is a GNU extension, available since glibc
2.1.
Since glibc 2.1, alphasort() calls strcoll(3); earlier it used str-
cmp(3).
EXAMPLE
#define _SVID_SOURCE
/* print files in current directory in reverse order */
#include
int
main(void)
{
struct dirent **namelist;
int n;
n = scandir(".", &namelist, 0, alphasort);
if (n < 0)
perror("scandir");
else {
while (n--) {
printf("%s\n", namelist[n]->d_name);
free(namelist[n]);
}
free(namelist);
}
}
SEE ALSO
closedir(3), fnmatch(3), opendir(3), readdir(3), rewinddir(3),
seekdir(3), strcmp(3), strcoll(3), strverscmp(3), telldir(3)
COLOPHON
This page is part of release 3.05 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
GNU 2007-07-26 SCANDIR(3)
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