files/t_chown.c

+/* t_chown.c
+
+   Demonstrate the use of the chown() system call to change the owner
+   and group of a file.
+
+   Usage: t_chown owner group [file...]
+
+   Either or both of owner and/or group can be specified as "-" to
+   leave them unchanged.
+*/
 #include <pwd.h>
 #include <grp.h>
 #include "ugid_functions.h"             /* Declarations of userIdFromName()
                                            and groupIdFromName() */
 #include "tlpi_hdr.h"
 
 int
 main(int argc, char *argv[])
 {
     uid_t uid;
     gid_t gid;
     int j;
     Boolean errFnd;
 
     if (argc < 3 || strcmp(argv[1], "--help") == 0)
         usageErr("%s owner group [file...]\n"
                 "        owner or group can be '-', "
                 "meaning leave unchanged\n", argv[0]);
 
     if (strcmp(argv[1], "-") == 0) {            /* "-" ==> don't change owner */
         uid = -1;
     } else {                                    /* Turn user name into UID */
         uid = userIdFromName(argv[1]);
         if (uid == -1)
             fatal("No such user (%s)", argv[1]);
     }
 
     if (strcmp(argv[2], "-") == 0) {            /* "-" ==> don't change group */
         gid = -1;
     } else {                                    /* Turn group name into GID */
         gid = groupIdFromName(argv[2]);
         if (gid == -1)
             fatal("No such group (%s)", argv[2]);
     }
 
     /* Change ownership of all files named in remaining arguments */
 
     errFnd = FALSE;
     for (j = 3; j < argc; j++) {
         if (chown(argv[j], uid, gid) == -1) {
             errMsg("chown: %s", argv[j]);
             errFnd = TRUE;
         }
     }
 
     exit(errFnd ? EXIT_FAILURE : EXIT_SUCCESS);
 }