diff options
Diffstat (limited to 'procps/renice.c')
| -rw-r--r-- | procps/renice.c | 132 |
1 files changed, 115 insertions, 17 deletions
diff --git a/procps/renice.c b/procps/renice.c index a6f0820df..d4ce66d2e 100644 --- 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 @@ * */ +/* 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 + +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; + } -extern int renice_main(int argc, char **argv) + return s; +} + +int renice_main(int argc, char **argv) { - int prio, status = EXIT_SUCCESS; + 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; - if (argc < 3) bb_show_usage(); + ++argv; - prio = atoi(*++argv); - if (prio > 20) prio = 20; - if (prio < -20) prio = -20; + /* 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); + /* 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; + } + } - if (setpriority(PRIO_PROCESS, ps, prio) == 0) { - printf("%d: old priority %d, new priority %d\n", ps, oldp, prio ); + /* 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 { - bb_perror_msg("%d: setpriority", ps); - status = EXIT_FAILURE; + 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; } - 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; } |