1 /* 2 * Copyright (c) 1988 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * This code is derived from software written by Ken Arnold and 6 * published in UNIX Review, Vol. 6, No. 8. 7 * 8 * Redistribution and use in source and binary forms are permitted 9 * provided that the above copyright notice and this paragraph are 10 * duplicated in all such forms and that any documentation, 11 * advertising materials, and other materials related to such 12 * distribution and use acknowledge that the software was developed 13 * by the University of California, Berkeley. The name of the 14 * University may not be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 19 * 20 */ 21 22 #ifndef lint 23 static char sccsid[] = "@(#)popen.c 5.7 (Berkeley) 02/14/89"; 24 #endif /* not lint */ 25 26 #include <sys/types.h> 27 #include <sys/signal.h> 28 #include <sys/wait.h> 29 #include <stdio.h> 30 31 /* 32 * Special version of popen which avoids call to shell. This insures noone 33 * may create a pipe to a hidden program as a side effect of a list or dir 34 * command. 35 */ 36 static int *pids; 37 static int fds; 38 39 FILE * 40 ftpd_popen(program, type) 41 char *program, *type; 42 { 43 register char *cp; 44 FILE *iop; 45 int argc, gargc, pdes[2], pid; 46 char **pop, *argv[100], *gargv[1000], *vv[2]; 47 extern char **glob(), **copyblk(), *strtok(), *malloc(); 48 49 if (*type != 'r' && *type != 'w' || type[1]) 50 return(NULL); 51 52 if (!pids) { 53 if ((fds = getdtablesize()) <= 0) 54 return(NULL); 55 if ((pids = (int *)malloc((u_int)(fds * sizeof(int)))) == NULL) 56 return(NULL); 57 bzero((char *)pids, fds * sizeof(int)); 58 } 59 if (pipe(pdes) < 0) 60 return(NULL); 61 62 /* break up string into pieces */ 63 for (argc = 0, cp = program;; cp = NULL) 64 if (!(argv[argc++] = strtok(cp, " \t\n"))) 65 break; 66 67 /* glob each piece */ 68 gargv[0] = argv[0]; 69 for (gargc = argc = 1; argv[argc]; argc++) { 70 if (!(pop = glob(argv[argc]))) { /* globbing failed */ 71 vv[0] = argv[argc]; 72 vv[1] = NULL; 73 pop = copyblk(vv); 74 } 75 argv[argc] = (char *)pop; /* save to free later */ 76 while (*pop && gargc < 1000) 77 gargv[gargc++] = *pop++; 78 } 79 gargv[gargc] = NULL; 80 81 iop = NULL; 82 switch(pid = vfork()) { 83 case -1: /* error */ 84 (void)close(pdes[0]); 85 (void)close(pdes[1]); 86 goto pfree; 87 /* NOTREACHED */ 88 case 0: /* child */ 89 if (*type == 'r') { 90 if (pdes[1] != 1) { 91 dup2(pdes[1], 1); 92 dup2(pdes[1], 2); /* stderr, too! */ 93 (void)close(pdes[1]); 94 } 95 (void)close(pdes[0]); 96 } else { 97 if (pdes[0] != 0) { 98 dup2(pdes[0], 0); 99 (void)close(pdes[0]); 100 } 101 (void)close(pdes[1]); 102 } 103 execv(gargv[0], gargv); 104 _exit(1); 105 } 106 /* parent; assume fdopen can't fail... */ 107 if (*type == 'r') { 108 iop = fdopen(pdes[0], type); 109 (void)close(pdes[1]); 110 } else { 111 iop = fdopen(pdes[1], type); 112 (void)close(pdes[0]); 113 } 114 pids[fileno(iop)] = pid; 115 116 pfree: for (argc = 1; argv[argc] != NULL; argc++) { 117 blkfree((char **)argv[argc]); 118 free((char *)argv[argc]); 119 } 120 return(iop); 121 } 122 123 ftpd_pclose(iop) 124 FILE *iop; 125 { 126 register int fdes; 127 int omask; 128 union wait stat_loc; 129 int pid; 130 131 /* 132 * pclose returns -1 if stream is not associated with a 133 * `popened' command, or, if already `pclosed'. 134 */ 135 if (pids == 0 || pids[fdes = fileno(iop)] == 0) 136 return(-1); 137 (void)fclose(iop); 138 omask = sigblock(sigmask(SIGINT)|sigmask(SIGQUIT)|sigmask(SIGHUP)); 139 while ((pid = wait(&stat_loc)) != pids[fdes] && pid != -1); 140 (void)sigsetmask(omask); 141 pids[fdes] = 0; 142 return(pid == -1 ? -1 : stat_loc.w_status); 143 } 144