Move sed over to the generic llist_t for append. Saves about 90 bytes.

[oweals/busybox.git] / procps / renice.c

diff --git a/procps/renice.c b/procps/renice.c
index 9180ebf8146dcddffda6d6f96e593104e3186b7b..d4ce66d2e97dfa274cec5868a15959b7a3c30c32 100644 (file)
--- a/procps/renice.c
+++ b/procps/renice.c
@@ -1,8 +1,8 @@
+/* vi: set sw=4 ts=4: */
 /*
- * Mini renice implementation for busybox
+ * renice implementation for busybox
  *
- *
- * Copyright (C) 2000 Dave 'Kill a Cop' Cinege <dcinege@psychosis.com>
+ * Copyright (C) 2005  Manuel Novoa III  <mjn3@codepoet.org>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -20,35 +20,133 @@
  *
  */
 
-#include "busybox.h"
+/* Notes:
+ *   Setting an absolute priority was obsoleted in SUSv2 and removed
+ *   in SUSv3.  However, the common linux version of renice does
+ *   absolute and not relative.  So we'll continue supporting absolute,
+ *   although the stdout logging has been removed since both SUSv2 and
+ *   SUSv3 specify that stdout isn't used.
+ *
+ *   This version is lenient in that it doesn't require any IDs.  The
+ *   options -p, -g, and -u are treated as mode switches for the
+ *   following IDs (if any).  Multiple switches are allowed.
+ */
+
 #include <stdio.h>
-#include <errno.h>
 #include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+#include <errno.h>
+#include <unistd.h>
 #include <sys/time.h>
 #include <sys/resource.h>
+#include "busybox.h"
 
+#if (PRIO_PROCESS < CHAR_MIN) || (PRIO_PROCESS > CHAR_MAX)
+#error Assumption violated : PRIO_PROCESS value
+#endif
+#if (PRIO_PGRP < CHAR_MIN) || (PRIO_PGRP > CHAR_MAX)
+#error Assumption violated : PRIO_PGRP value
+#endif
+#if (PRIO_USER < CHAR_MIN) || (PRIO_USER > CHAR_MAX)
+#error Assumption violated : PRIO_USER value
+#endif
 
-extern int renice_main(int argc, char **argv)
+static inline int int_add_no_wrap(int a, int b)
 {
-       int prio, status = EXIT_SUCCESS;
-       
-       if (argc < 3)   show_usage();
-               
-       prio = atoi(*++argv);
-       if (prio > 20)          prio = 20;
-       if (prio < -20)         prio = -20;
-       
+       int s = a + b;
+
+       if (b < 0) {
+               if (s > a) s = INT_MIN;
+       } else {
+               if (s < a) s = INT_MAX;
+       }
+
+       return s;
+}
+
+int renice_main(int argc, char **argv)
+{
+       static const char Xetpriority_msg[] = "%d : %cetpriority";
+
+       int retval = EXIT_SUCCESS;
+       int which = PRIO_PROCESS;       /* Default 'which' value. */
+       int use_relative = 0;
+       int adjustment, new_priority;
+       id_t who;
+
+       ++argv;
+
+       /* Check if we are using a relative adjustment. */
+       if (argv[0] && (argv[0][0] == '-') && (argv[0][1] == 'n') && !argv[0][2]) {
+               use_relative = 1;
+               ++argv;
+       }
+
+       if (!*argv) {                           /* No args?  Then show usage. */
+               bb_show_usage();
+       }
+
+       /* Get the priority adjustment (absolute or relative). */
+       adjustment = bb_xgetlarg(*argv, 10, INT_MIN, INT_MAX);
+
        while (*++argv) {
-               int ps = atoi(*argv);
-               int oldp = getpriority(PRIO_PROCESS, ps);
-               
-               if (setpriority(PRIO_PROCESS, ps, prio) == 0) {
-                       printf("%d: old priority %d, new priority %d\n", ps, oldp, prio );
+               /* Check for a mode switch. */
+               if ((argv[0][0] == '-') && argv[0][1] && !argv[0][2]) {
+                       static const char opts[]
+                               = { 'p', 'g', 'u', 0, PRIO_PROCESS, PRIO_PGRP, PRIO_USER };
+                       const char *p;
+                       if ((p = strchr(opts, argv[0][1]))) {
+                               which = p[4];
+                               continue;
+                       }
+               }
+
+               /* Process an ID arg. */
+               if (which == PRIO_USER) {
+                       struct passwd *p;
+                       if (!(p = getpwnam(*argv))) {
+                               bb_error_msg("unknown user: %s", *argv);
+                               goto HAD_ERROR;
+                       }
+                       who = p->pw_uid;
+               } else {
+                       char *e;
+                       errno = 0;
+                       who = strtoul(*argv, &e, 10);
+                       if (*e || (*argv == e) || errno) {
+                               bb_error_msg("bad value: %s", *argv);
+                               goto HAD_ERROR;
+                       }
+               }
+
+               /* Get priority to use, and set it. */
+               if (use_relative) {
+                       int old_priority;
+
+                       errno = 0;       /* Needed for getpriority error detection. */
+                       old_priority = getpriority(which, who);
+                       if (errno) {
+                               bb_perror_msg(Xetpriority_msg, who, 'g');
+                               goto HAD_ERROR;
+                       }
+
+                       new_priority = int_add_no_wrap(old_priority, adjustment);
                } else {
-                       perror_msg("%d: setpriority", ps);
-                       status = EXIT_FAILURE;
+                       new_priority = adjustment;
                }
+
+               if (setpriority(which, who, new_priority) == 0) {
+                       continue;
+               }
+
+               bb_perror_msg(Xetpriority_msg, who, 's');
+       HAD_ERROR:
+               retval = EXIT_FAILURE;
        }
 
-       return status;
+       /* No need to check for errors outputing to stderr since, if it
+        * was used, the HAD_ERROR label was reached and retval was set. */
+
+       return retval;
 }