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| 1 /* Subprocesses with pipes. |
| 2 |
| 3 Copyright (C) 2005, 2006, 2007, 2008 Free Software Foundation, Inc. |
| 4 |
| 5 This program is free software: you can redistribute it and/or modify |
| 6 it under the terms of the GNU General Public License as published by |
| 7 the Free Software Foundation, either version 3 of the License, or |
| 8 (at your option) any later version. |
| 9 |
| 10 This program is distributed in the hope that it will be useful, |
| 11 but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 GNU General Public License for more details. |
| 14 |
| 15 You should have received a copy of the GNU General Public License |
| 16 along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 17 |
| 18 /* Written by Juan Manuel Guerrero <juan.guerrero@gmx.de>. */ |
| 19 |
| 20 |
| 21 #include <config.h> |
| 22 |
| 23 #include "subpipe.h" |
| 24 |
| 25 #include <errno.h> |
| 26 #include <fcntl.h> |
| 27 #include <sys/stat.h> |
| 28 #include <process.h> |
| 29 #include <signal.h> |
| 30 #include <stdio.h> |
| 31 #include <stdlib.h> |
| 32 #include <string.h> |
| 33 #include <unistd.h> |
| 34 #include "xalloc.h" |
| 35 |
| 36 |
| 37 #ifndef STDIN_FILENO |
| 38 # define STDIN_FILENO 0 |
| 39 #endif |
| 40 #ifndef STDOUT_FILENO |
| 41 # define STDOUT_FILENO 1 |
| 42 #endif |
| 43 |
| 44 |
| 45 #include "error.h" |
| 46 |
| 47 #include "gettext.h" |
| 48 #define _(Msgid) gettext (Msgid) |
| 49 |
| 50 |
| 51 /* Initialize this module. */ |
| 52 |
| 53 |
| 54 static int old_stdin; |
| 55 static int old_stdout; |
| 56 static char **arguments; |
| 57 static char tmp_file_name[2][L_tmpnam]; |
| 58 |
| 59 #define remove_tmp_file(fd, name) \ |
| 60 do { \ |
| 61 close ((fd)); \ |
| 62 if (unlink ((name))) \ |
| 63 error (EXIT_FAILURE, 0, _("removing of `%s' failed"), (name)); \ |
| 64 } while (0) |
| 65 |
| 66 |
| 67 void |
| 68 init_subpipe(void) |
| 69 { |
| 70 char *tmpdir; |
| 71 int fd; |
| 72 |
| 73 tmpdir = getenv("TMPDIR"); |
| 74 if (tmpdir == NULL) |
| 75 tmpdir = getenv("TMP"); |
| 76 if (tmpdir == NULL) |
| 77 tmpdir = getenv("TEMP"); |
| 78 if (access(tmpdir, D_OK)) |
| 79 tmpdir = "."; |
| 80 |
| 81 strcpy(tmp_file_name[0], tmpdir); |
| 82 strcat(tmp_file_name[0], "/bnXXXXXX"); |
| 83 fd = mkstemp(tmp_file_name[0]); |
| 84 if (fd < 0) |
| 85 error(EXIT_FAILURE, 0, _("creation of a temporary file failed")); |
| 86 close (fd); |
| 87 |
| 88 strcpy(tmp_file_name[1], tmpdir); |
| 89 strcat(tmp_file_name[1], "/bnXXXXXX"); |
| 90 fd = mkstemp(tmp_file_name[1]); |
| 91 if (fd < 0) |
| 92 error(EXIT_FAILURE, 0, _("creation of a temporary file failed")); |
| 93 close (fd); |
| 94 } |
| 95 |
| 96 |
| 97 /* Create a subprocess that is run as a filter. ARGV is the |
| 98 NULL-terminated argument vector for the subprocess. Store read and |
| 99 write file descriptors for communication with the subprocess into |
| 100 FD[0] and FD[1]: input meant for the process can be written into |
| 101 FD[0], and output from the process can be read from FD[1]. Return |
| 102 the subprocess id. |
| 103 |
| 104 Because DOS has neither fork nor pipe functionality to run the subprocess |
| 105 as a filter, the filter is reproduced using temporary files. First bison's |
| 106 stdout is redirected to a temporary file. After bison has produced all of |
| 107 is output, this file is closed and connected to m4's stdin. All m4's output |
| 108 is redirected from m4's stdout to a second temporary file and reopened as |
| 109 bison's stdin. */ |
| 110 |
| 111 pid_t |
| 112 create_subpipe(char const *const *argv, int fd[2]) |
| 113 { |
| 114 int argc; |
| 115 int from_in_fd; /* pipe from bison to m4. */ |
| 116 pid_t pid; |
| 117 |
| 118 |
| 119 pid = getpid(); |
| 120 |
| 121 /* |
| 122 * Save original stdin and stdout |
| 123 * for later restauration. |
| 124 */ |
| 125 old_stdin = dup(STDIN_FILENO); |
| 126 if (old_stdin < 0) |
| 127 error(EXIT_FAILURE, 0, _("saving stdin failed")); |
| 128 |
| 129 old_stdout = dup(STDOUT_FILENO); |
| 130 if (old_stdout < 0) |
| 131 error(EXIT_FAILURE, 0, _("saving stdout failed")); |
| 132 |
| 133 /* |
| 134 * Save argv for later use. |
| 135 */ |
| 136 for (argc = 0; argv[argc]; argc++) |
| 137 ; |
| 138 argc++; |
| 139 arguments = xmalloc(argc * sizeof(arguments[0])); |
| 140 for (argc = 0; argv[argc]; argc++) |
| 141 { |
| 142 arguments[argc] = xmalloc((strlen(argv[argc]) + 1) * sizeof(arguments[0][0])
); |
| 143 strcpy(arguments[argc], argv[argc]); |
| 144 } |
| 145 arguments[argc] = NULL; |
| 146 |
| 147 /* |
| 148 * All bison's output will be gathered in this temporary file |
| 149 * and will be redirected to m4's stdin. |
| 150 */ |
| 151 from_in_fd = open(tmp_file_name[0], O_WRONLY | O_CREAT | O_TRUNC, S_IWUSR); |
| 152 if (from_in_fd < 0) |
| 153 error(EXIT_FAILURE, 0, _("opening of tmpfile failed")); |
| 154 if (dup2(from_in_fd, STDOUT_FILENO) < 0) |
| 155 { |
| 156 remove_tmp_file(from_in_fd, tmp_file_name[0]); |
| 157 error(EXIT_FAILURE, 0, _("redirecting bison's stdout to the temporary file f
ailed")); |
| 158 } |
| 159 close(from_in_fd); |
| 160 |
| 161 |
| 162 fd[0] = STDOUT_FILENO; |
| 163 return pid; |
| 164 } |
| 165 |
| 166 |
| 167 /* A signal handler that just records that a signal has happened. */ |
| 168 static int child_interrupted; |
| 169 |
| 170 static void |
| 171 signal_catcher(int signo) |
| 172 { |
| 173 child_interrupted++; |
| 174 } |
| 175 |
| 176 |
| 177 void |
| 178 end_of_output_subpipe(pid_t pid, int fd[2]) |
| 179 { |
| 180 char *program; |
| 181 int from_out_fd = open(tmp_file_name[0], O_RDONLY, S_IRUSR);
/* pipe from bison to m4. */ |
| 182 int to_in_fd = open(tmp_file_name[1], O_WRONLY | O_CREAT | O_TRUNC, S_IWUSR);
/* pipe from m4 to bison. */ |
| 183 int status; |
| 184 void (*previous_handler)(int); |
| 185 |
| 186 |
| 187 program = strrchr(arguments[0], '/'); |
| 188 if (program) |
| 189 program++; |
| 190 else |
| 191 program = arguments[0]; |
| 192 |
| 193 /* |
| 194 * Redirect bison's output to m4's stdin. |
| 195 */ |
| 196 if (from_out_fd < 0) |
| 197 error(EXIT_FAILURE, 0, _("opening of tmpfile failed")); |
| 198 if (dup2(from_out_fd, STDIN_FILENO) < 0) |
| 199 { |
| 200 remove_tmp_file(from_out_fd, tmp_file_name[0]); |
| 201 error(EXIT_FAILURE, 0, _("redirecting m4's stdin from the temporary file fai
led")); |
| 202 } |
| 203 close(from_out_fd); |
| 204 |
| 205 /* |
| 206 * All m4's output will be gathered in this temporary file |
| 207 * and will be redirected to bison's stdin. |
| 208 */ |
| 209 if (to_in_fd < 0) |
| 210 { |
| 211 remove_tmp_file(STDIN_FILENO, tmp_file_name[0]); |
| 212 error(EXIT_FAILURE, 0, _("opening of a temporary file failed")); |
| 213 } |
| 214 if (dup2(to_in_fd, STDOUT_FILENO) < 0) |
| 215 { |
| 216 remove_tmp_file(STDIN_FILENO, tmp_file_name[0]); |
| 217 remove_tmp_file(to_in_fd, tmp_file_name[1]); |
| 218 error(EXIT_FAILURE, 0, _("redirecting m4's stdout to a temporary file failed
")); |
| 219 } |
| 220 close(to_in_fd); |
| 221 |
| 222 /* |
| 223 * Run m4. |
| 224 */ |
| 225 child_interrupted = 0; |
| 226 errno = 0; |
| 227 previous_handler = signal(SIGINT, signal_catcher); |
| 228 status = spawnvp(P_WAIT, program, arguments); |
| 229 signal(SIGINT, previous_handler); |
| 230 if (child_interrupted) |
| 231 { |
| 232 remove_tmp_file(STDIN_FILENO, tmp_file_name[0]); |
| 233 remove_tmp_file(STDOUT_FILENO, tmp_file_name[1]); |
| 234 error(EXIT_FAILURE, 0, _("subsidiary program `%s' interrupted"), program); |
| 235 } |
| 236 if (status) |
| 237 { |
| 238 remove_tmp_file(STDIN_FILENO, tmp_file_name[0]); |
| 239 remove_tmp_file(STDOUT_FILENO, tmp_file_name[1]); |
| 240 error(EXIT_FAILURE, 0, _(errno == ENOENT |
| 241 ? "subsidiary program `%s' not found" |
| 242 : status < 1 |
| 243 ? "subsidiary program `%s' failed" |
| 244 : "subsidiary program `%s' failed (status=%i, errno
=%i)"), program, status, errno); |
| 245 } |
| 246 |
| 247 |
| 248 /* |
| 249 * Redirect m4's output to bison's stdin. |
| 250 */ |
| 251 if (dup2(old_stdout, STDOUT_FILENO) < 0) |
| 252 error(EXIT_FAILURE, 0, "restore of bison's stdout failed"); |
| 253 close(old_stdout); |
| 254 to_in_fd = open(tmp_file_name[1], O_RDONLY, S_IRUSR); /* pipe from m4 to biso
n. */ |
| 255 if (to_in_fd < 0) |
| 256 { |
| 257 remove_tmp_file(STDIN_FILENO, tmp_file_name[0]); |
| 258 error(EXIT_FAILURE, 0, _("opening of tmpfile failed")); |
| 259 } |
| 260 if (dup2(to_in_fd, STDIN_FILENO) < 0) |
| 261 { |
| 262 remove_tmp_file(STDIN_FILENO, tmp_file_name[0]); |
| 263 remove_tmp_file(to_in_fd, tmp_file_name[1]); |
| 264 error(EXIT_FAILURE, -1, "dup2"); |
| 265 error(EXIT_FAILURE, 0, _("redirecting bison's stdin from the temporary file
failed")); |
| 266 } |
| 267 close(to_in_fd); |
| 268 |
| 269 |
| 270 fd[1] = STDIN_FILENO; |
| 271 } |
| 272 |
| 273 |
| 274 /* Free resources, unlink temporary files and restore stdin and stdout. */ |
| 275 |
| 276 void |
| 277 reap_subpipe(pid_t pid, char const *program) |
| 278 { |
| 279 int argc; |
| 280 |
| 281 for (argc = 0; arguments[argc]; argc++) |
| 282 free(arguments[argc]); |
| 283 free(arguments); |
| 284 |
| 285 if (unlink(tmp_file_name[0])) |
| 286 error(EXIT_FAILURE, 0, _("removing of `%s' failed"), tmp_file_name[0]); |
| 287 if (unlink(tmp_file_name[1])) |
| 288 error(EXIT_FAILURE, 0, _("removing of `%s' failed"), tmp_file_name[1]); |
| 289 |
| 290 if (dup2(old_stdin, STDIN_FILENO) < 0) |
| 291 error(EXIT_FAILURE, 0, "restore of bison's stdin failed"); |
| 292 close(old_stdin); |
| 293 } |
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