/* vi: set sw=4 ts=4: */ /* * renice implementation for busybox * * 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 * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * */ /* 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 <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 static inline int int_add_no_wrap(int a, int b) { 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) { /* 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 { new_priority = adjustment; } if (setpriority(which, who, new_priority) == 0) { continue; } bb_perror_msg(Xetpriority_msg, who, '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; }