random small size optimizations

[oweals/busybox.git] / loginutils / deluser.c

diff --git a/loginutils/deluser.c b/loginutils/deluser.c
index 795dae49f568b66bda3ca8bbb4ed61c474520445..d07fd22aca3fb3ae2696bc0f32dc54ff9380d227 100644 (file)
--- a/loginutils/deluser.c
+++ b/loginutils/deluser.c
@@ -12,85 +12,72 @@
 
 #include "busybox.h"
 
-/* where to start and stop deletion */
-typedef struct {
-       size_t start;
-       size_t stop;
-} Bounds;
-
-/* An interesting side-effect of boundary()'s
- * implementation is that the first user (typically root)
- * cannot be removed.  Let's call it a feature. */
-static inline Bounds boundary(const char *buffer, const char *login)
-{
-       char needle[256];
-       char *start;
-       char *stop;
-       Bounds b;
-
-       snprintf(needle, 256, "\n%s:", login);
-       needle[255] = 0;
-       start = strstr(buffer, needle);
-       if (!start) {
-               b.start = 0;
-               b.stop = 0;
-               return b;
-       }
-       start++;
-
-       stop = strchr(start, '\n');
-       b.start = start - buffer;
-       b.stop = stop - buffer;
-       return b;
-}
-
-/* grep -v ^login (except it only deletes the first match) */
-/* ...in fact, I think I'm going to simplify this later */
 static void del_line_matching(const char *login, const char *filename)
 {
-       char *buffer;
+       char *line;
        FILE *passwd;
-       Bounds b;
-       struct stat statbuf;
+       int len = strlen(login);
+       int found = 0;
+       llist_t *plist = NULL;
 
+       passwd = fopen_or_warn(filename, "r");
+       if (!passwd) return;
 
-       if ((passwd = fopen_or_warn(filename, "r"))) {
-               // Remove pointless const.
-               xstat((char *)filename, &statbuf);
-               buffer = (char *) xmalloc(statbuf.st_size * sizeof(char));
-               fread(buffer, statbuf.st_size, sizeof(char), passwd);
-               fclose(passwd);
-               /* find the user to remove */
-               b = boundary(buffer, login);
-               if (b.stop != 0) {
-                       /* write the file w/o the user */
-                       if ((passwd = fopen_or_warn(filename, "w"))) {
-                               fwrite(buffer, (b.start - 1), sizeof(char), passwd);
-                               fwrite(&buffer[b.stop], (statbuf.st_size - b.stop), sizeof(char), passwd);
-                               fclose(passwd);
-                       }
+       while ((line = xmalloc_fgets(passwd))) {
+               if (!strncmp(line, login, len)
+                && line[len] == ':'
+               ) {
+                       found++;
+                       free(line);
                } else {
+                       llist_add_to_end(&plist, line);
+               }
+       }
+
+       if (!ENABLE_FEATURE_CLEAN_UP) {
+               if (!found) {
+                       bb_error_msg("can't find '%s' in '%s'", login, filename);
+                       return;
+               }
+               passwd = fopen_or_warn(filename, "w");
+               if (passwd)
+                       while ((line = llist_pop(&plist)))
+                               fputs(line, passwd);
+       } else {
+               if (!found) {
                        bb_error_msg("can't find '%s' in '%s'", login, filename);
+                       goto clean_up;
+               }
+               fclose(passwd);
+               passwd = fopen_or_warn(filename, "w");
+               if (passwd) {
+ clean_up:
+                       while ((line = llist_pop(&plist))) {
+                               if (found) fputs(line, passwd);
+                               free(line);
+                       }
+                       fclose(passwd);
                }
-               free(buffer);
        }
 }
 
 int deluser_main(int argc, char **argv)
 {
-       if (argc != 2) {
+       if (argc != 2)
                bb_show_usage();
-       } else {
-               if (ENABLE_DELUSER && applet_name[3] == 'u') {
-                       del_line_matching(argv[1], bb_path_passwd_file);
-                       if (ENABLE_FEATURE_SHADOWPASSWDS)
-                               del_line_matching(argv[1], bb_path_shadow_file);
-               }
-               del_line_matching(argv[1], bb_path_group_file);
+
+       if (ENABLE_DELUSER
+        && (!ENABLE_DELGROUP || applet_name[3] == 'u')
+       ) {
+               del_line_matching(argv[1], bb_path_passwd_file);
                if (ENABLE_FEATURE_SHADOWPASSWDS)
-                       del_line_matching(argv[1], bb_path_gshadow_file);
+                       del_line_matching(argv[1], bb_path_shadow_file);
        }
-       return (EXIT_SUCCESS);
+       del_line_matching(argv[1], bb_path_group_file);
+       if (ENABLE_FEATURE_SHADOWPASSWDS)
+               del_line_matching(argv[1], bb_path_gshadow_file);
+
+       return EXIT_SUCCESS;
 }
 
 /* $Id: deluser.c,v 1.4 2003/07/14 20:20:45 andersen Exp $ */