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→{{header|C}}: Add alternate solution using BSD fts(3).
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=={{header|C}}==
==={{libheader|POSIX}}===
{{works with|POSIX|.1-2001}}
Line 176 ⟶ 177:
walker(".", ".\\.c$");
return 0;
}</lang>
==={{libheader|BSD libc}}===
With the [http://www.openbsd.org/cgi-bin/man.cgi?query=fts&apropos=0&sektion=3&manpath=OpenBSD+Current&arch=i386&format=html fts(3)] functions from 4.4BSD, this program can sort the files, and can also detect cycles (when a link puts a directory inside itself). This program makes a ''logical traversal'' that follows symbolic links to directories.
{{works with|OpenBSD|4.9}}
<lang c>#include <sys/types.h>
#include <err.h>
#include <errno.h>
#include <fnmatch.h>
#include <fts.h>
#include <string.h>
#include <stdio.h>
/* Compare files by name. */
int
entcmp(const FTSENT **a, const FTSENT **b)
{
return strcmp((*a)->fts_name, (*b)->fts_name);
}
/*
* Print all files in the directory tree that match the glob pattern.
* Example: pmatch("/usr/src", "*.c");
*/
void
pmatch(char *dir, const char *pattern)
{
FTS *tree;
FTSENT *f;
char *argv[] = { dir, NULL };
/*
* FTS_LOGICAL follows symbolic links, including links to other
* directories. It detects cycles, so we never have an infinite
* loop. FTS_NOSTAT is because we never use f->statp. It uses
* our entcmp() to sort files by name.
*/
tree = fts_open(argv, FTS_LOGICAL | FTS_NOSTAT, entcmp);
if (tree == NULL)
err(1, "fts_open");
/*
* Iterate files in tree. This iteration always skips
* "." and ".." because we never use FTS_SEEDOT.
*/
while (f = fts_read(tree)) {
switch (f->fts_info) {
case FTS_DNR: /* Cannot read directory */
case FTS_ERR: /* Miscellaneous error */
case FTS_NS: /* stat() error */
/* Show error, then continue to next files. */
warn("%s", f->fts_path);
continue;
case FTS_DP:
/* Ignore post-order visit to directory. */
continue;
}
/*
* Check if name matches pattern. If so, then print
* path. This check uses FNM_PERIOD, so "*.c" will not
* match ".invisible.c".
*/
if (fnmatch(pattern, f->fts_name, FNM_PERIOD) == 0)
puts(f->fts_path);
/*
* A cycle happens when a symbolic link (or perhaps a
* hard link) puts a directory inside itself. Tell user
* when this happens.
*/
if (f->fts_info == FTS_DC)
warnx("%s: cycle in directory tree", f->fts_path);
}
/* fts_read() sets errno = 0 unless it has error. */
if (errno != 0)
err(1, "fts_read");
if (fts_close(tree) < 0)
err(1, "fts_close");
}
int
main()
{
pmatch(".", "*.c");
return 0;
}</lang>
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