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author | Richard Maw <richard.maw@codethink.co.uk> | 2012-01-17 14:43:55 +0000 |
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committer | Richard Maw <richard.maw@codethink.co.uk> | 2012-01-17 14:43:55 +0000 |
commit | 2de9abc5c9d40b3c716307d67d16146f823fd554 (patch) | |
tree | 6979db67934ddc8b564150b465846a383b428ff8 /gnulib/lib/popen.c | |
parent | 33cc1c6fda6e72a7bae1401e9b2cec495a4d3ff1 (diff) | |
download | patch-baserock/bootstrap.tar.gz |
add the output of bootstrapbaserock/bootstrap-pass2baserock/bootstrap
Diffstat (limited to 'gnulib/lib/popen.c')
m--------- | gnulib | 0 | ||||
-rw-r--r-- | gnulib/lib/popen.c | 103 |
2 files changed, 103 insertions, 0 deletions
diff --git a/gnulib b/gnulib deleted file mode 160000 -Subproject 443bc5ffcf7429e557f4a371b0661abe98ddbc1 diff --git a/gnulib/lib/popen.c b/gnulib/lib/popen.c new file mode 100644 index 0000000..4330479 --- /dev/null +++ b/gnulib/lib/popen.c @@ -0,0 +1,103 @@ +/* Open a stream to a sub-process. + Copyright (C) 2009-2011 Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. */ + +/* Written by Eric Blake <ebb9@byu.net>, 2009. */ + +#include <config.h> + +/* Specification. */ +#include <stdio.h> + +#if HAVE_POPEN + +# include <errno.h> +# include <fcntl.h> +# include <stdlib.h> +# include <unistd.h> + +# undef popen + +FILE * +rpl_popen (const char *filename, const char *mode) +{ + /* The mingw popen works fine, and all other platforms have fcntl. + The bug of the child clobbering its own file descriptors if stdin + or stdout was closed in the parent can be worked around by + opening those two fds as close-on-exec to begin with. */ + /* Cygwin 1.5.x also has a bug where the popen fd is improperly + marked close-on-exec, and if the application undoes this, then + the fd leaks into subsequent popen calls. We could work around + this by maintaining a list of all fd's opened by popen, and + temporarily marking them cloexec around the real popen call, but + we would also have to override pclose, and the bookkeepping seems + extreme given that cygwin 1.7 no longer has the bug. */ + FILE *result; + int cloexec0 = fcntl (STDIN_FILENO, F_GETFD); + int cloexec1 = fcntl (STDOUT_FILENO, F_GETFD); + int saved_errno; + + /* If either stdin or stdout was closed (that is, fcntl failed), + then we open a dummy close-on-exec fd to occupy that slot. That + way, popen's internal use of pipe() will not contain either fd 0 + or 1, overcoming the fact that the child process blindly calls + close() on the parent's end of the pipe without first checking + whether it is clobbering the fd just placed there via dup2(); the + exec will get rid of the dummy fd's in the child. Fortunately, + closed stderr in the parent does not cause problems in the + child. */ + if (cloexec0 < 0) + { + if (open ("/dev/null", O_RDONLY) != STDIN_FILENO + || fcntl (STDIN_FILENO, F_SETFD, + fcntl (STDIN_FILENO, F_GETFD) | FD_CLOEXEC) == -1) + abort (); + } + if (cloexec1 < 0) + { + if (open ("/dev/null", O_RDONLY) != STDOUT_FILENO + || fcntl (STDOUT_FILENO, F_SETFD, + fcntl (STDOUT_FILENO, F_GETFD) | FD_CLOEXEC) == -1) + abort (); + } + result = popen (filename, mode); + /* Now, close any dummy fd's created in the parent. */ + saved_errno = errno; + if (cloexec0 < 0) + close (STDIN_FILENO); + if (cloexec1 < 0) + close (STDOUT_FILENO); + errno = saved_errno; + return result; +} + +#else +/* Native Woe32 API. */ + +# include <string.h> + +FILE * +popen (const char *filename, const char *mode) +{ + /* Use binary mode by default. */ + if (strcmp (mode, "r") == 0) + mode = "rb"; + else if (strcmp (mode, "w") == 0) + mode = "wb"; + + return _popen (filename, mode); +} + +#endif |