The scandir() function scans the directory dirp, calling filter() on each directory entry. Entries for which filter() returns nonzero 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.

Command line execution

Terminalbash
sed as the comparison function compar(). The former sorts directory entries using strcoll(3), the latter using strverscmp(3) on the strings (*a)->d_name and (*b)->d_name.  $ vim print_files_in_current_directory.c  #include <dirent.h> #include <stdio.h> #include <stdlib.h>   int main(void) {         struct dirent **namelist;         int n;           n = scandir(".", &namelist, NULL, alphasort);         if (n < 0)                 perror("scandir");         else {                 while (n--) {                         printf("%s\n", namelist[n]->d_name);                         free(namelist[n]);                 }                 free(namelist);         }         return 0; }  $ gcc -o print_files_in_current_directory print_files_in_current_directory.c   $ ./print_files_in_current_directory

Implementation details

The alphasort() and versionsort() functions can be used as the comparison function compar(). The former sorts directory entries using strcoll(3), the latter using strverscmp(3) on the strings (*a)->d_name and (*b)->d_name. $ vim print_files_in_current_directory.c #include <dirent.h> #include <stdio.h> #include <stdlib.h> int main(void) { struct dirent **namelist; int n; n = scandir(".", &namelist, NULL, alphasort); if (n < 0) perror("scandir"); else { while (n--) { printf("%s\n", namelist[n]->d_name); free(namelist[n]); } free(namelist); } return 0; } $ gcc -o print_files_in_current_directory print_files_in_current_directory.c $ ./print_files_in_current_directory

Gotchas and common issues

  • Permission checks - verify user access rights and sudo privileges before executing system-level operations.

  • Environment configuration - double-check path variables and dependency versions to prevent runtime failures.

  • Backup safeguards - maintain configuration backups before applying system or database modifications.

Following these steps ensures clean configuration and reliable execution for c program to print files in current directory in reverse order.