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utils-std

Collection of commonly available Unix tools git clone https://anongit.hacktivis.me/git/utils-std.git/

renice.c (3389B)

    

  1. // utils-std: Collection of commonly available Unix tools
  2. // SPDX-FileCopyrightText: 2017 Haelwenn (lanodan) Monnier <contact+utils@hacktivis.me>
  3. // SPDX-License-Identifier: MPL-2.0
  5. #define _POSIX_C_SOURCE 200809L
  6. #define _XOPEN_SOURCE 700 // getpriority, setpriority
  8. #include "../lib/getopt_nolong.h"
  10. #include <errno.h>
  11. #include <stdio.h>        // fprintf
  12. #include <stdlib.h>       // abort
  13. #include <string.h>       // strerror
  14. #include <sys/resource.h> // getpriority, setpriority
  15. #include <unistd.h>       // getopt, nice
  17. const char *argv0 = "renice";
  19. static int
  20. renice(int which, id_t who, int adj)
  21. {
  22. 	const char *which_s = NULL;
  23. 	switch(which)
  24. 	{
  25. 	case PRIO_PROCESS:
  26. 		which_s = "PRIO_PROCESS";
  27. 		break;
  28. 	case PRIO_PGRP:
  29. 		which_s = "PRIO_PGRP";
  30. 		break;
  31. 	case PRIO_USER:
  32. 		which_s = "PRIO_USER";
  33. 		break;
  34. 	default:
  35. 		which_s = NULL;
  36. 	}
  38. 	errno = 0;
  39. 	int prio = getpriority(which, who);
  40. 	if(errno != 0)
  41. 	{
  42. 		fprintf(stderr, "renice: error: getpriority(%s, %d): %s\n", which_s, who, strerror(errno));
  43. 		return -1;
  44. 	}
  46. 	prio += adj;
  48. 	if(setpriority(which, who, prio) != 0)
  49. 	{
  50. 		fprintf(stderr,
  51. 		        "renice: error: setpriority(%s, %d, %d): %s\n",
  52. 		        which_s,
  53. 		        who,
  54. 		        prio,
  55. 		        strerror(errno));
  56. 		return -1;
  57. 	}
  59. 	return 0;
  60. }
  62. static void
  63. usage(void)
  64. {
  65. 	fprintf(stderr, "\
  66. Usage: renice [-p] -n adj PID...\n\
  67.        renice  -g  -n adj PGID...\n\
  68.        renice  -u  -n adj UID...\n\
  69. ");
  70. }
  72. int
  73. main(int argc, char *argv[])
  74. {
  75. 	long adj = 0;
  76. 	int which = PRIO_PROCESS;
  78. 	for(int c = -1; (c = getopt_nolong(argc, argv, ":gpun:")) != -1;)
  79. 	{
  80. 		char *endptr = NULL;
  82. 		switch(c)
  83. 		{
  84. 		case 'g':
  85. 			which = PRIO_PGRP;
  86. 			break;
  87. 		case 'p':
  88. 			which = PRIO_PROCESS;
  89. 			break;
  90. 		case 'u':
  91. 			which = PRIO_USER;
  92. 			break;
  93. 		case 'n':
  94. 			adj = strtol(optarg, &endptr, 10);
  96. 			if(endptr && *endptr != 0) errno = EINVAL;
  97. 			if(errno != 0)
  98. 			{
  99. 				fprintf(stderr,
  100. 				        "renice: error: Failed parsing '%s' as a number: %s\n",
  101. 				        optarg,
  102. 				        strerror(errno));
  103. 				usage();
  104. 				return 1;
  105. 			}
  106. 			if(adj < PRIO_MIN)
  107. 			{
  108. 				fprintf(stderr, "renice: error: '-n %ld' is lower than PRIO_MIN(%d)\n", adj, PRIO_MIN);
  109. 				return 1;
  110. 			}
  111. 			if(adj > PRIO_MAX)
  112. 			{
  113. 				fprintf(stderr, "renice: error: '-n %ld' is greater than PRIO_MAX(%d)\n", adj, PRIO_MAX);
  114. 				return 1;
  115. 			}
  116. 			if(adj == 0)
  117. 			{
  118. 				fprintf(stderr, "renice: error: '-n 0' makes no sense\n");
  119. 				return 1;
  120. 			}
  121. 			break;
  122. 		case ':':
  123. 			fprintf(stderr, "renice: error: Missing operand for option: '-%c'\n", optopt);
  124. 			usage();
  125. 			return 1;
  126. 		case '?':
  127. 			if(!got_long_opt) fprintf(stderr, "renice: error: Unrecognised option: '-%c'\n", optopt);
  128. 			usage();
  129. 			return 1;
  130. 		default:
  131. 			abort();
  132. 		}
  133. 	}
  135. 	argc -= optind;
  136. 	argv += optind;
  138. 	if(argc == 0)
  139. 	{
  140. 		fprintf(stderr, "renice: error: No IDs passed\n");
  141. 		usage();
  142. 		return 1;
  143. 	}
  145. 	if(adj == 0)
  146. 	{
  147. 		fprintf(stderr, "renice: error: Mandatory option '-n adj' not passed\n");
  148. 		usage();
  149. 		return 1;
  150. 	}
  152. 	for(int i = 0; i < argc; i++)
  153. 	{
  154. 		char *endptr = NULL;
  155. 		char *arg = argv[i];
  157. 		long who = strtol(arg, &endptr, 0);
  158. 		if(endptr && *endptr != 0) errno = EINVAL;
  160. 		if(errno != 0)
  161. 		{
  162. 			fprintf(stderr,
  163. 			        "renice: error: Failed parsing argument '%s' as a number: %s\n",
  164. 			        arg,
  165. 			        strerror(errno));
  166. 			usage();
  167. 			return 1;
  168. 		}
  170. 		if(renice(which, who, adj) != 0) return 1;
  171. 	}
  173. 	return 0;
  174. }