| /* vi: set sw=4 ts=4: */ |
| /* |
| * renice implementation for busybox |
| * |
| * Copyright (C) 2005 Manuel Novoa III <mjn3@codepoet.org> |
| * |
| * Licensed under GPLv2 or later, see file LICENSE in this source tree. |
| */ |
| |
| /* 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. |
| */ |
| |
| //usage:#define renice_trivial_usage |
| //usage: "[-n] PRIORITY [[-p | -g | -u] ID...]..." |
| //usage:#define renice_full_usage "\n\n" |
| //usage: "Change scheduling priority of a running process\n" |
| //usage: "\n -n Add PRIORITY to current nice value" |
| //usage: "\n Without -n, nice value is set to PRIORITY" |
| //usage: "\n -p Process ids (default)" |
| //usage: "\n -g Process group ids" |
| //usage: "\n -u Process user names" |
| |
| #include "libbb.h" |
| #include <sys/resource.h> |
| |
| void BUG_bad_PRIO_PROCESS(void); |
| void BUG_bad_PRIO_PGRP(void); |
| void BUG_bad_PRIO_USER(void); |
| |
| int renice_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
| int renice_main(int argc UNUSED_PARAM, char **argv) |
| { |
| static const char Xetpriority_msg[] ALIGN1 = "%cetpriority"; |
| |
| int retval = EXIT_SUCCESS; |
| int which = PRIO_PROCESS; /* Default 'which' value. */ |
| int use_relative = 0; |
| int adjustment, new_priority; |
| unsigned who; |
| char *arg; |
| |
| /* Yes, they are not #defines in glibc 2.4! #if won't work */ |
| if (PRIO_PROCESS < CHAR_MIN || PRIO_PROCESS > CHAR_MAX) |
| BUG_bad_PRIO_PROCESS(); |
| if (PRIO_PGRP < CHAR_MIN || PRIO_PGRP > CHAR_MAX) |
| BUG_bad_PRIO_PGRP(); |
| if (PRIO_USER < CHAR_MIN || PRIO_USER > CHAR_MAX) |
| BUG_bad_PRIO_USER(); |
| |
| arg = *++argv; |
| |
| /* Check if we are using a relative adjustment. */ |
| if (arg && arg[0] == '-' && arg[1] == 'n') { |
| use_relative = 1; |
| if (!arg[2]) |
| arg = *++argv; |
| else |
| arg += 2; |
| } |
| |
| if (!arg) { /* No args? Then show usage. */ |
| bb_show_usage(); |
| } |
| |
| /* Get the priority adjustment (absolute or relative). */ |
| adjustment = xatoi_range(arg, INT_MIN/2, INT_MAX/2); |
| |
| while ((arg = *++argv) != NULL) { |
| /* Check for a mode switch. */ |
| if (arg[0] == '-' && arg[1]) { |
| static const char opts[] ALIGN1 = { |
| 'p', 'g', 'u', 0, PRIO_PROCESS, PRIO_PGRP, PRIO_USER |
| }; |
| const char *p = strchr(opts, arg[1]); |
| if (p) { |
| which = p[4]; |
| if (!arg[2]) |
| continue; |
| arg += 2; |
| } |
| } |
| |
| /* Process an ID arg. */ |
| if (which == PRIO_USER) { |
| struct passwd *p; |
| p = getpwnam(arg); |
| if (!p) { |
| bb_error_msg("unknown user %s", arg); |
| goto HAD_ERROR; |
| } |
| who = p->pw_uid; |
| } else { |
| who = bb_strtou(arg, NULL, 10); |
| if (errno) { |
| bb_error_msg("invalid number '%s'", arg); |
| 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, 'g'); |
| goto HAD_ERROR; |
| } |
| |
| new_priority = old_priority + adjustment; |
| } else { |
| new_priority = adjustment; |
| } |
| |
| if (setpriority(which, who, new_priority) == 0) { |
| continue; |
| } |
| |
| bb_perror_msg(Xetpriority_msg, 's'); |
| HAD_ERROR: |
| retval = EXIT_FAILURE; |
| } |
| |
| /* 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; |
| } |