/* 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. */ //config:config RENICE //config: bool "renice (3.8 kb)" //config: default y //config: help //config: Renice alters the scheduling priority of one or more running //config: processes. //applet:IF_RENICE(APPLET_NOEXEC(renice, renice, BB_DIR_USR_BIN, BB_SUID_DROP, renice)) //kbuild:lib-$(CONFIG_RENICE) += renice.o //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" 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 */ BUILD_BUG_ON(PRIO_PROCESS < CHAR_MIN || PRIO_PROCESS > CHAR_MAX); BUILD_BUG_ON(PRIO_PGRP < CHAR_MIN || PRIO_PGRP > CHAR_MAX); BUILD_BUG_ON(PRIO_USER < CHAR_MIN || PRIO_USER > CHAR_MAX); 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; /* NB: use of getpwnam makes it risky to be NOFORK, switch to getpwnam_r? */ 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 outputting to stderr since, if it * was used, the HAD_ERROR label was reached and retval was set. */ return retval; }