Mercurial > gnulib
changeset 16339:993344da76d0
popen: Make more robust on Windows.
* lib/popen.c: On native Windows, use the _popen based code even if
HAVE_POPEN is set.
* doc/posix-functions/popen.texi: Mention necessity of COMSPEC
environment variable on native Windows.
| author | Bruno Haible <bruno@clisp.org> |
|---|---|
| date | Tue, 31 Jan 2012 12:15:46 +0100 |
| parents | 5770cc0ba46f |
| children | 3e1267814983 |
| files | ChangeLog doc/posix-functions/popen.texi lib/popen.c |
| diffstat | 3 files changed, 30 insertions(+), 19 deletions(-) [+] |
line wrap: on
line diff
--- a/ChangeLog Tue Jan 31 12:13:29 2012 +0100 +++ b/ChangeLog Tue Jan 31 12:15:46 2012 +0100 @@ -1,3 +1,11 @@ +2012-01-31 Bruno Haible <bruno@clisp.org> + + popen: Make more robust on Windows. + * lib/popen.c: On native Windows, use the _popen based code even if + HAVE_POPEN is set. + * doc/posix-functions/popen.texi: Mention necessity of COMSPEC + environment variable on native Windows. + 2012-01-30 Bruno Haible <bruno@clisp.org> pclose: Fix typo.
--- a/doc/posix-functions/popen.texi Tue Jan 31 12:13:29 2012 +0100 +++ b/doc/posix-functions/popen.texi Tue Jan 31 12:15:46 2012 +0100 @@ -20,6 +20,9 @@ Portability problems not fixed by Gnulib: @itemize @item +On native Windows platforms, this functions terminates the current process +with exit code 127 if the environment variable @code{COMSPEC} is not set. +@item Some platforms mistakenly set the close-on-exec bit, then if it is cleared by the application, the platform then leaks file descriptors from earlier @code{popen} calls into subsequent @code{popen} children:
--- a/lib/popen.c Tue Jan 31 12:13:29 2012 +0100 +++ b/lib/popen.c Tue Jan 31 12:15:46 2012 +0100 @@ -21,7 +21,24 @@ /* Specification. */ #include <stdio.h> -#if HAVE_POPEN +#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__ +/* Native Windows 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); +} + +#else # include <errno.h> # include <fcntl.h> @@ -33,7 +50,7 @@ FILE * rpl_popen (const char *filename, const char *mode) { - /* The mingw popen works fine, and all other platforms have fcntl. + /* All other platforms have popen and 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. */ @@ -83,21 +100,4 @@ return result; } -#else -/* Native Windows 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