1/* vi: set sw=4 ts=4: */ 2/* 3 * renice implementation for busybox 4 * 5 * Copyright (C) 2005 Manuel Novoa III <mjn3@codepoet.org> 6 * 7 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball. 8 */ 9 10/* Notes: 11 * Setting an absolute priority was obsoleted in SUSv2 and removed 12 * in SUSv3. However, the common linux version of renice does 13 * absolute and not relative. So we'll continue supporting absolute, 14 * although the stdout logging has been removed since both SUSv2 and 15 * SUSv3 specify that stdout isn't used. 16 * 17 * This version is lenient in that it doesn't require any IDs. The 18 * options -p, -g, and -u are treated as mode switches for the 19 * following IDs (if any). Multiple switches are allowed. 20 */ 21 22#include "libbb.h" 23#include <sys/resource.h> 24 25void BUG_bad_PRIO_PROCESS(void); 26void BUG_bad_PRIO_PGRP(void); 27void BUG_bad_PRIO_USER(void); 28 29int renice_main(int argc, char **argv); 30int renice_main(int argc, char **argv) 31{ 32 static const char Xetpriority_msg[] ALIGN1 = "%cetpriority"; 33 34 int retval = EXIT_SUCCESS; 35 int which = PRIO_PROCESS; /* Default 'which' value. */ 36 int use_relative = 0; 37 int adjustment, new_priority; 38 unsigned who; 39 char *arg; 40 41 /* Yes, they are not #defines in glibc 2.4! #if won't work */ 42 if (PRIO_PROCESS < CHAR_MIN || PRIO_PROCESS > CHAR_MAX) 43 BUG_bad_PRIO_PROCESS(); 44 if (PRIO_PGRP < CHAR_MIN || PRIO_PGRP > CHAR_MAX) 45 BUG_bad_PRIO_PGRP(); 46 if (PRIO_USER < CHAR_MIN || PRIO_USER > CHAR_MAX) 47 BUG_bad_PRIO_USER(); 48 49 arg = *++argv; 50 51 /* Check if we are using a relative adjustment. */ 52 if (arg && arg[0] == '-' && arg[1] == 'n') { 53 use_relative = 1; 54 if (!arg[2]) 55 arg = *++argv; 56 else 57 arg += 2; 58 } 59 60 if (!arg) { /* No args? Then show usage. */ 61 bb_show_usage(); 62 } 63 64 /* Get the priority adjustment (absolute or relative). */ 65 adjustment = xatoi_range(arg, INT_MIN/2, INT_MAX/2); 66 67 while ((arg = *++argv) != NULL) { 68 /* Check for a mode switch. */ 69 if (arg[0] == '-' && arg[1]) { 70 static const char opts[] ALIGN1 = { 71 'p', 'g', 'u', 0, PRIO_PROCESS, PRIO_PGRP, PRIO_USER 72 }; 73 const char *p = strchr(opts, arg[1]); 74 if (p) { 75 which = p[4]; 76 if (!arg[2]) 77 continue; 78 arg += 2; 79 } 80 } 81 82 /* Process an ID arg. */ 83 if (which == PRIO_USER) { 84 struct passwd *p; 85 p = getpwnam(arg); 86 if (!p) { 87 bb_error_msg("unknown user: %s", arg); 88 goto HAD_ERROR; 89 } 90 who = p->pw_uid; 91 } else { 92 who = bb_strtou(arg, NULL, 10); 93 if (errno) { 94 bb_error_msg("bad value: %s", arg); 95 goto HAD_ERROR; 96 } 97 } 98 99 /* Get priority to use, and set it. */ 100 if (use_relative) { 101 int old_priority; 102 103 errno = 0; /* Needed for getpriority error detection. */ 104 old_priority = getpriority(which, who); 105 if (errno) { 106 bb_perror_msg(Xetpriority_msg, 'g'); 107 goto HAD_ERROR; 108 } 109 110 new_priority = old_priority + adjustment; 111 } else { 112 new_priority = adjustment; 113 } 114 115 if (setpriority(which, who, new_priority) == 0) { 116 continue; 117 } 118 119 bb_perror_msg(Xetpriority_msg, 's'); 120 HAD_ERROR: 121 retval = EXIT_FAILURE; 122 } 123 124 /* No need to check for errors outputing to stderr since, if it 125 * was used, the HAD_ERROR label was reached and retval was set. */ 126 127 return retval; 128} 129