1 /*- 2 * Copyright (c) 1988, 1993, 1994 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #if 0 31 #ifndef lint 32 static char const copyright[] = 33 "@(#) Copyright (c) 1988, 1993, 1994\n\ 34 The Regents of the University of California. All rights reserved.\n"; 35 #endif /* not lint */ 36 37 #ifndef lint 38 static char sccsid[] = "@(#)sleep.c 8.3 (Berkeley) 4/2/94"; 39 #endif /* not lint */ 40 #endif 41 #include <sys/cdefs.h> 42 __FBSDID("$FreeBSD$"); 43 44 #include <ctype.h> 45 #include <limits.h> 46 #include <stdio.h> 47 #include <stdlib.h> 48 #include <time.h> 49 #include <unistd.h> 50 51 void usage(void); 52 53 int 54 main(int argc, char *argv[]) 55 { 56 struct timespec time_to_sleep; 57 long l; 58 int neg; 59 char *p; 60 61 if (argc != 2) { 62 usage(); 63 return(1); 64 } 65 66 p = argv[1]; 67 68 /* Skip over leading whitespaces. */ 69 while (isspace((unsigned char)*p)) 70 ++p; 71 72 /* Check for optional `+' or `-' sign. */ 73 neg = 0; 74 if (*p == '-') { 75 neg = 1; 76 ++p; 77 if (!isdigit((unsigned char)*p) && *p != '.') { 78 usage(); 79 return(1); 80 } 81 } 82 else if (*p == '+') 83 ++p; 84 85 /* Calculate seconds. */ 86 if (isdigit((unsigned char)*p)) { 87 l = strtol(p, &p, 10); 88 if (l > INT_MAX) { 89 /* 90 * Avoid overflow when `seconds' is huge. This assumes 91 * that the maximum value for a time_t is <= INT_MAX. 92 */ 93 l = INT_MAX; 94 } 95 } else 96 l = 0; 97 time_to_sleep.tv_sec = (time_t)l; 98 99 /* Calculate nanoseconds. */ 100 time_to_sleep.tv_nsec = 0; 101 102 if (*p == '.') { /* Decimal point. */ 103 l = 100000000L; 104 do { 105 if (isdigit((unsigned char)*++p)) 106 time_to_sleep.tv_nsec += (*p - '0') * l; 107 else 108 break; 109 l /= 10; 110 } while (l); 111 } 112 113 if (!neg && (time_to_sleep.tv_sec > 0 || time_to_sleep.tv_nsec > 0)) 114 (void)nanosleep(&time_to_sleep, (struct timespec *)NULL); 115 116 return(0); 117 } 118 119 void 120 usage(void) 121 { 122 const char msg[] = "usage: sleep seconds\n"; 123 124 write(STDERR_FILENO, msg, sizeof(msg) - 1); 125 } 126