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nohup.c revision 1.1.1.2 
      1 /*
      2  * Copyright (c) 1989, 1993
      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 #ifndef lint
     35 static char copyright[] =
     36 "@(#) Copyright (c) 1989, 1993\n\
     37 	The Regents of the University of California.  All rights reserved.\n";
     38 #endif /* not lint */
     39 
     40 #ifndef lint
     41 static char sccsid[] = "@(#)nohup.c	8.1 (Berkeley) 6/6/93";
     42 #endif /* not lint */
     43 
     44 #include <sys/param.h>
     45 #include <sys/stat.h>
     46 
     47 #include <errno.h>
     48 #include <fcntl.h>
     49 #include <signal.h>
     50 #include <stdio.h>
     51 #include <stdlib.h>
     52 #include <string.h>
     53 #include <unistd.h>
     54 
     55 void dofile __P((void));
     56 void usage __P((void));
     57 
     58 int
     59 main(argc, argv)
     60 	int argc;
     61 	char *argv[];
     62 {
     63 	if (argc < 2)
     64 		usage();
     65 
     66 	if (isatty(STDOUT_FILENO))
     67 		dofile();
     68 	if (isatty(STDERR_FILENO) && dup2(STDOUT_FILENO, STDERR_FILENO) == -1) {
     69 		/* may have just closed stderr */
     70 		(void)fprintf(stdin, "nohup: %s\n", strerror(errno));
     71 		exit(1);
     72 	}
     73 
     74 	(void)signal(SIGHUP, SIG_IGN);
     75 	(void)signal(SIGQUIT, SIG_IGN);
     76 
     77 	execvp(argv[1], &argv[1]);
     78 	(void)fprintf(stderr,
     79 	    "nohup: %s: %s\n", argv[1], strerror(errno));
     80 	exit(1);
     81 }
     82 
     83 void
     84 dofile()
     85 {
     86 	int fd;
     87 	char *p, path[MAXPATHLEN];
     88 
     89 #define	FILENAME	"nohup.out"
     90 	p = FILENAME;
     91 	if ((fd = open(p, O_RDWR|O_CREAT, S_IRUSR | S_IWUSR)) >= 0)
     92 		goto dupit;
     93 	if (p = getenv("HOME")) {
     94 		(void)strcpy(path, p);
     95 		(void)strcat(path, "/");
     96 		(void)strcat(path, FILENAME);
     97 		if ((fd = open(p = path,
     98 		    O_RDWR|O_CREAT, S_IRUSR | S_IWUSR)) >= 0)
     99 			goto dupit;
    100 	}
    101 	(void)fprintf(stderr, "nohup: can't open a nohup.out file.\n");
    102 	exit(1);
    103 
    104 dupit:	(void)lseek(fd, (off_t)0, SEEK_END);
    105 	if (dup2(fd, STDOUT_FILENO) == -1) {
    106 		(void)fprintf(stderr, "nohup: %s\n", strerror(errno));
    107 		exit(1);
    108 	}
    109 	(void)fprintf(stderr, "sending output to %s\n", p);
    110 }
    111 
    112 void
    113 usage()
    114 {
    115 	(void)fprintf(stderr, "usage: nohup command\n");
    116 	exit(1);
    117 }
    118