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 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #if 0 35 #ifndef lint 36 static char const copyright[] = 37 "@(#) Copyright (c) 1988, 1993, 1994\n\ 38 The Regents of the University of California. All rights reserved.\n"; 39 #endif /* not lint */ 40 41 #ifndef lint 42 static char sccsid[] = "@(#)sleep.c 8.3 (Berkeley) 4/2/94"; 43 #endif /* not lint */ 44 #endif 45 #include <sys/cdefs.h> 46 __FBSDID("$FreeBSD$"); 47 48 #include <ctype.h> 49 #include <limits.h> 50 #include <stdio.h> 51 #include <stdlib.h> 52 #include <time.h> 53 #include <unistd.h> 54 55 void usage(void); 56 57 int 58 main(int argc, char *argv[]) 59 { 60 struct timespec time_to_sleep; 61 long l; 62 int neg; 63 char *p; 64 65 if (argc != 2) { 66 usage(); 67 return(1); 68 } 69 70 p = argv[1]; 71 72 /* Skip over leading whitespaces. */ 73 while (isspace((unsigned char)*p)) 74 ++p; 75 76 /* Check for optional `+' or `-' sign. */ 77 neg = 0; 78 if (*p == '-') { 79 neg = 1; 80 ++p; 81 if (!isdigit((unsigned char)*p) && *p != '.') { 82 usage(); 83 return(1); 84 } 85 } 86 else if (*p == '+') 87 ++p; 88 89 /* Calculate seconds. */ 90 if (isdigit((unsigned char)*p)) { 91 l = strtol(p, &p, 10); 92 if (l > INT_MAX) { 93 /* 94 * Avoid overflow when `seconds' is huge. This assumes 95 * that the maximum value for a time_t is >= INT_MAX. 96 */ 97 l = INT_MAX; 98 } 99 } else 100 l = 0; 101 time_to_sleep.tv_sec = (time_t)l; 102 103 /* Calculate nanoseconds. */ 104 time_to_sleep.tv_nsec = 0; 105 106 if (*p == '.') { /* Decimal point. */ 107 l = 100000000L; 108 do { 109 if (isdigit((unsigned char)*++p)) 110 time_to_sleep.tv_nsec += (*p - '0') * l; 111 else 112 break; 113 l /= 10; 114 } while (l); 115 } 116 117 if (!neg && (time_to_sleep.tv_sec > 0 || time_to_sleep.tv_nsec > 0)) 118 (void)nanosleep(&time_to_sleep, (struct timespec *)NULL); 119 120 return(0); 121 } 122 123 void 124 usage(void) 125 { 126 const char msg[] = "usage: sleep seconds\n"; 127 128 write(STDERR_FILENO, msg, sizeof(msg) - 1); 129 } 130