acl/acl_view.c

+/* acl_view.c
+
+   Display the access control list (ACL) on a file.
+
+   Usage: acl_view [-d] file
+
+   If the '-d' option is specified, then the default ACL is displayed (and
+   'file' must be a directory), otherwise the access ACL is displayed.
+
+   This program is Linux-specific. ACLs are supported since Linux 2.6.
+   To build this program, you must have the ACL library (libacl) installed
+   on your system.
+*/
 #include <acl/libacl.h>
 #include <sys/acl.h>
 #include "ugid_functions.h"
 #include "tlpi_hdr.h"
 
 static void
 usageError(char *progName)
 {
     fprintf(stderr, "Usage: %s [-d] filename\n", progName);
     exit(EXIT_FAILURE);
 }
 
 int
 main(int argc, char *argv[])
 {
     acl_t acl;
     acl_type_t type;
     acl_entry_t entry;
     acl_tag_t tag;
     uid_t *uidp;
     gid_t *gidp;
     acl_permset_t permset;
     char *name;
     int entryId, permVal, opt;
 
     type = ACL_TYPE_ACCESS;
     while ((opt = getopt(argc, argv, "d")) != -1) {
         switch (opt) {
         case 'd': type = ACL_TYPE_DEFAULT;      break;
         case '?': usageError(argv[0]);
         }
     }
 
     if (optind + 1 != argc)
         usageError(argv[0]);
 
     acl = acl_get_file(argv[optind], type);
     if (acl == NULL)
         errExit("acl_get_file");
 
     /* Walk through each entry in this ACL */
 
     for (entryId = ACL_FIRST_ENTRY; ; entryId = ACL_NEXT_ENTRY) {
 
         if (acl_get_entry(acl, entryId, &entry) != 1)
             break;                      /* Exit on error or no more entries */
 
         /* Retrieve and display tag type */
 
         if (acl_get_tag_type(entry, &tag) == -1)
             errExit("acl_get_tag_type");
 
         printf("%-12s", (tag == ACL_USER_OBJ) ?  "user_obj" :
                         (tag == ACL_USER) ?      "user" :
                         (tag == ACL_GROUP_OBJ) ? "group_obj" :
                         (tag == ACL_GROUP) ?     "group" :
                         (tag == ACL_MASK) ?      "mask" :
                         (tag == ACL_OTHER) ?     "other" : "???");
 
         /* Retrieve and display optional tag qualifier */
 
         if (tag == ACL_USER) {
             uidp = acl_get_qualifier(entry);
             if (uidp == NULL)
                 errExit("acl_get_qualifier");
 
             name = userNameFromId(*uidp);
             if (name == NULL)
                 printf("%-8d ", *uidp);
             else
                 printf("%-8s ", name);
 
             if (acl_free(uidp) == -1)
                 errExit("acl_free");
 
         } else if (tag == ACL_GROUP) {
             gidp = acl_get_qualifier(entry);
             if (gidp == NULL)
                 errExit("acl_get_qualifier");
 
             name = groupNameFromId(*gidp);
             if (name == NULL)
                 printf("%-8d ", *gidp);
             else
                 printf("%-8s ", name);
 
             if (acl_free(gidp) == -1)
                 errExit("acl_free");
 
         } else {
             printf("         ");
         }
 
         /* Retrieve and display permissions */
 
         if (acl_get_permset(entry, &permset) == -1)
             errExit("acl_get_permset");
 
         permVal = acl_get_perm(permset, ACL_READ);
         if (permVal == -1)
             errExit("acl_get_perm - ACL_READ");
         printf("%c", (permVal == 1) ? 'r' : '-');
         permVal = acl_get_perm(permset, ACL_WRITE);
         if (permVal == -1)
             errExit("acl_get_perm - ACL_WRITE");
         printf("%c", (permVal == 1) ? 'w' : '-');
         permVal = acl_get_perm(permset, ACL_EXECUTE);
         if (permVal == -1)
             errExit("acl_get_perm - ACL_EXECUTE");
         printf("%c", (permVal == 1) ? 'x' : '-');
 
         printf("\n");
     }
 
     if (acl_free(acl) == -1)
         errExit("acl_free");
 
     exit(EXIT_SUCCESS);
 }