Computer Science
SCANDIR(3) Linux Programmer's Manual SCANDIR(3)
NAME
scandir, alphasort - scan a directory for matching entries
SYNOPSIS
#include <dirent.h>
int scandir(const char *dir, struct dirent ***namelist,
int (*select)(const struct dirent *),
int (*compar)(const struct dirent **, const struct dirent **));
int alphasort(const struct dirent **a, const struct dirent **b);
DESCRIPTION
The scandir() function scans the directory dir, calling
select() on each directory entry. Entries for which
select() returns non-zero are stored in strings allocated
via malloc(), sorted using qsort() with the comparison
function compar(), and collected in array namelist which
is allocated via malloc(). If select is NULL, all entries
are selected.
The alphasort() function can be used as the comparison
function for the scandir() function to sort the directory
entries into alphabetical order. Its parameters are the
two directory entries, a and b, to compare.
RETURN VALUE
The scandir() function returns the number of directory
entries selected or -1 if an error occurs.
The alphasort() function returns an integer less than,
equal to, or greater than zero if the first argument is
considered to be respectively less than, equal to, or
greater than the second.
ERRORS
ENOMEM Insufficient memory to complete the operation.
CONFORMING TO
BSD 4.3
EXAMPLE
/* print files in current directory in reverse order */
#include <dirent.h>
main(){
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);
}
SEE ALSO
opendir(3), readdir(3), closedir(3), rewinddir(3),
telldir(3), seekdir(3).
GNU 11 April 1996 1
Back to the index