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Annotation of 43BSDReno/libexec/ftpd/popen.c, revision 1.1

1.1     ! root        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: (1) source distributions retain this entire copyright
        !            10:  * notice and comment, and (2) distributions including binaries display
        !            11:  * the following acknowledgement:  ``This product includes software
        !            12:  * developed by the University of California, Berkeley and its contributors''
        !            13:  * in the documentation or other materials provided with the distribution
        !            14:  * and in all advertising materials mentioning features or use of this
        !            15:  * software. Neither the name of the University nor the names of its
        !            16:  * contributors may be used to endorse or promote products derived
        !            17:  * from this software without specific prior written permission.
        !            18:  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
        !            19:  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
        !            20:  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
        !            21:  *
        !            22:  */
        !            23: 
        !            24: #ifndef lint
        !            25: static char sccsid[] = "@(#)popen.c    5.8 (Berkeley) 6/1/90";
        !            26: #endif /* not lint */
        !            27: 
        !            28: #include <sys/types.h>
        !            29: #include <sys/signal.h>
        !            30: #include <sys/wait.h>
        !            31: #include <stdio.h>
        !            32: 
        !            33: /*
        !            34:  * Special version of popen which avoids call to shell.  This insures noone
        !            35:  * may create a pipe to a hidden program as a side effect of a list or dir
        !            36:  * command.
        !            37:  */
        !            38: static int *pids;
        !            39: static int fds;
        !            40: 
        !            41: FILE *
        !            42: ftpd_popen(program, type)
        !            43:        char *program, *type;
        !            44: {
        !            45:        register char *cp;
        !            46:        FILE *iop;
        !            47:        int argc, gargc, pdes[2], pid;
        !            48:        char **pop, *argv[100], *gargv[1000], *vv[2];
        !            49:        extern char **glob(), **copyblk(), *strtok(), *malloc();
        !            50: 
        !            51:        if (*type != 'r' && *type != 'w' || type[1])
        !            52:                return(NULL);
        !            53: 
        !            54:        if (!pids) {
        !            55:                if ((fds = getdtablesize()) <= 0)
        !            56:                        return(NULL);
        !            57:                if ((pids = (int *)malloc((u_int)(fds * sizeof(int)))) == NULL)
        !            58:                        return(NULL);
        !            59:                bzero((char *)pids, fds * sizeof(int));
        !            60:        }
        !            61:        if (pipe(pdes) < 0)
        !            62:                return(NULL);
        !            63: 
        !            64:        /* break up string into pieces */
        !            65:        for (argc = 0, cp = program;; cp = NULL)
        !            66:                if (!(argv[argc++] = strtok(cp, " \t\n")))
        !            67:                        break;
        !            68: 
        !            69:        /* glob each piece */
        !            70:        gargv[0] = argv[0];
        !            71:        for (gargc = argc = 1; argv[argc]; argc++) {
        !            72:                if (!(pop = glob(argv[argc]))) {        /* globbing failed */
        !            73:                        vv[0] = argv[argc];
        !            74:                        vv[1] = NULL;
        !            75:                        pop = copyblk(vv);
        !            76:                }
        !            77:                argv[argc] = (char *)pop;               /* save to free later */
        !            78:                while (*pop && gargc < 1000)
        !            79:                        gargv[gargc++] = *pop++;
        !            80:        }
        !            81:        gargv[gargc] = NULL;
        !            82: 
        !            83:        iop = NULL;
        !            84:        switch(pid = vfork()) {
        !            85:        case -1:                        /* error */
        !            86:                (void)close(pdes[0]);
        !            87:                (void)close(pdes[1]);
        !            88:                goto pfree;
        !            89:                /* NOTREACHED */
        !            90:        case 0:                         /* child */
        !            91:                if (*type == 'r') {
        !            92:                        if (pdes[1] != 1) {
        !            93:                                dup2(pdes[1], 1);
        !            94:                                dup2(pdes[1], 2);       /* stderr, too! */
        !            95:                                (void)close(pdes[1]);
        !            96:                        }
        !            97:                        (void)close(pdes[0]);
        !            98:                } else {
        !            99:                        if (pdes[0] != 0) {
        !           100:                                dup2(pdes[0], 0);
        !           101:                                (void)close(pdes[0]);
        !           102:                        }
        !           103:                        (void)close(pdes[1]);
        !           104:                }
        !           105:                execv(gargv[0], gargv);
        !           106:                _exit(1);
        !           107:        }
        !           108:        /* parent; assume fdopen can't fail...  */
        !           109:        if (*type == 'r') {
        !           110:                iop = fdopen(pdes[0], type);
        !           111:                (void)close(pdes[1]);
        !           112:        } else {
        !           113:                iop = fdopen(pdes[1], type);
        !           114:                (void)close(pdes[0]);
        !           115:        }
        !           116:        pids[fileno(iop)] = pid;
        !           117: 
        !           118: pfree: for (argc = 1; argv[argc] != NULL; argc++) {
        !           119:                blkfree((char **)argv[argc]);
        !           120:                free((char *)argv[argc]);
        !           121:        }
        !           122:        return(iop);
        !           123: }
        !           124: 
        !           125: ftpd_pclose(iop)
        !           126:        FILE *iop;
        !           127: {
        !           128:        register int fdes;
        !           129:        int omask;
        !           130:        union wait stat_loc;
        !           131:        int pid;
        !           132: 
        !           133:        /*
        !           134:         * pclose returns -1 if stream is not associated with a
        !           135:         * `popened' command, or, if already `pclosed'.
        !           136:         */
        !           137:        if (pids == 0 || pids[fdes = fileno(iop)] == 0)
        !           138:                return(-1);
        !           139:        (void)fclose(iop);
        !           140:        omask = sigblock(sigmask(SIGINT)|sigmask(SIGQUIT)|sigmask(SIGHUP));
        !           141:        while ((pid = wait(&stat_loc)) != pids[fdes] && pid != -1);
        !           142:        (void)sigsetmask(omask);
        !           143:        pids[fdes] = 0;
        !           144:        return(pid == -1 ? -1 : stat_loc.w_status);
        !           145: }

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