Mercurial > hg > octave-kai > gnulib-hg
changeset 1822:b0ce344d4fda
*** empty log message ***
| author | Jim Meyering <jim@meyering.net> |
|---|---|
| date | Sat, 01 May 1999 04:13:56 +0000 |
| parents | e182ba5dd68f |
| children | 93ecfb08bb9c |
| files | lib/dup2.c m4/ChangeLog |
| diffstat | 2 files changed, 70 insertions(+), 0 deletions(-) [+] |
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new file mode 100644 --- /dev/null +++ b/lib/dup2.c @@ -0,0 +1,66 @@ +/* Duplicate an open file descriptor to a specified file descriptor. + Copyright 1999 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 2, 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, write to the Free Software Foundation, + Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ + +/* written by Paul Eggert */ + +#if HAVE_CONFIG_H +# include <config.h> +#endif + +#include <errno.h> +#ifndef errno +extern int errno; +#endif + +#if HAVE_FCNTL_H +# include <fcntl.h> +#endif + +#if HAVE_UNISTD_H +# include <unistd.h> +#endif + +#ifndef F_DUPFD +static int +dupfd (int fd, int desired_fd) +{ + int duplicated_fd = dup (fd); + if (duplicated_fd < 0 || duplicated_fd == desired_fd) + return duplicated_fd; + else + { + int r = dupfd (fd, desired_fd); + int e = errno; + close (duplicated_fd); + errno = e; + return r; + } +} +#endif + +int +dup2 (int fd, int desired_fd) +{ + if (fd == desired_fd) + return fd; + close (desired_fd); +#ifdef F_DUPFD + return fcntl (fd, F_DUPFD, desired_fd); +#else + return dupfd (fd, desired_fd); +#endif +}