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Annotation of src/usr.bin/make/cmd_exec.c, Revision 1.10

1.10    ! chl         1: /*     $OpenBSD: cmd_exec.c,v 1.9 2016/03/05 13:12:12 espie Exp $ */
1.1       espie       2: /*
                      3:  * Copyright (c) 2001 Marc Espie.
                      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:  *
                     14:  * THIS SOFTWARE IS PROVIDED BY THE OPENBSD PROJECT AND CONTRIBUTORS
                     15:  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
                     16:  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
                     17:  * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OPENBSD
                     18:  * PROJECT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
                     19:  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
                     20:  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
                     21:  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
                     22:  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
                     23:  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
                     24:  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
                     25:  */
                     26:
                     27: #include <sys/types.h>
                     28: #include <sys/wait.h>
                     29: #include <errno.h>
                     30: #include <stdio.h>
                     31: #include <unistd.h>
                     32: #include "config.h"
                     33: #include "defines.h"
                     34: #include "cmd_exec.h"
                     35: #include "buf.h"
                     36: #include "memory.h"
                     37: #include "pathnames.h"
                     38:
                     39: char *
1.5       espie      40: Cmd_Exec(const char *cmd, char **err)
1.1       espie      41: {
1.6       espie      42:        char    *args[4];       /* Args for invoking the shell */
                     43:        int     fds[2];         /* Pipe streams */
                     44:        pid_t   cpid;           /* Child PID */
                     45:        char    *result;        /* Result */
                     46:        int     status;         /* Command exit status */
                     47:        BUFFER  buf;            /* Buffer to store the result. */
                     48:        char    *cp;            /* Pointer into result. */
                     49:        ssize_t cc;             /* Characters read from pipe. */
                     50:        size_t  length;         /* Total length of result. */
                     51:
                     52:
                     53:        *err = NULL;
                     54:
                     55:        /* Set up arguments for the shell. */
                     56:        args[0] = "sh";
                     57:        args[1] = "-c";
                     58:        args[2] = (char *)cmd;
                     59:        args[3] = NULL;
                     60:
                     61:        /* Open a pipe for retrieving shell's output. */
                     62:        if (pipe(fds) == -1) {
                     63:                *err = "Couldn't create pipe for \"%s\"";
                     64:                goto bad;
1.3       millert    65:        }
1.1       espie      66:
1.6       espie      67:        /* Fork */
                     68:        switch (cpid = fork()) {
                     69:        case 0:
                     70:                /* Close input side of pipe */
                     71:                (void)close(fds[0]);
                     72:
                     73:                /* Duplicate the output stream to the shell's output, then
                     74:                 * shut the extra thing down. Note we don't fetch the error
                     75:                 * stream: user can use redirection to grab it as this goes
                     76:                 * through /bin/sh.
                     77:                 */
                     78:                if (fds[1] != 1) {
                     79:                        (void)dup2(fds[1], 1);
                     80:                        (void)close(fds[1]);
                     81:                }
                     82:
                     83:                (void)execv(_PATH_BSHELL, args);
                     84:                _exit(1);
                     85:                /*NOTREACHED*/
                     86:
                     87:        case -1:
                     88:                *err = "Couldn't exec \"%s\"";
                     89:                goto bad;
                     90:
                     91:        default:
                     92:                /* No need for the writing half. */
                     93:                (void)close(fds[1]);
                     94:
                     95:                Buf_Init(&buf, MAKE_BSIZE);
                     96:
                     97:                do {
                     98:                        char   grab[BUFSIZ];
                     99:
                    100:                        cc = read(fds[0], grab, sizeof(grab));
                    101:                        if (cc > 0)
                    102:                                Buf_AddChars(&buf, cc, grab);
                    103:                } while (cc > 0 || (cc == -1 && errno == EINTR));
                    104:
                    105:                /* Close the input side of the pipe.  */
                    106:                (void)close(fds[0]);
                    107:
                    108:                /* Wait for the child to exit.  */
1.9       espie     109:                while (waitpid(cpid, &status, 0) == -1 && errno == EINTR)
1.6       espie     110:                        continue;
                    111:
                    112:                if (cc == -1)
                    113:                        *err = "Couldn't read shell's output for \"%s\"";
                    114:
                    115:                if (status)
                    116:                        *err = "\"%s\" returned non-zero status";
                    117:
                    118:                length = Buf_Size(&buf);
                    119:                result = Buf_Retrieve(&buf);
                    120:
                    121:                /* The result is null terminated, Convert newlines to spaces. */
                    122:                cp = result + length - 1;
                    123:
                    124:                if (cp >= result && *cp == '\n')
                    125:                        /* A final newline is just stripped.  */
                    126:                        *cp-- = '\0';
                    127:
                    128:                while (cp >= result) {
                    129:                        if (*cp == '\n')
                    130:                                *cp = ' ';
                    131:                        cp--;
                    132:                }
                    133:                break;
1.1       espie     134:        }
1.6       espie     135:        return result;
                    136:     bad:
                    137:        return estrdup("");
1.1       espie     138: }
                    139: