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author | Jim Meyering <jim@meyering.net> | 1999-05-01 04:15:09 +0000 |
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committer | Jim Meyering <jim@meyering.net> | 1999-05-01 04:15:09 +0000 |
commit | 9a067599377f27bdc0831c233c7eeeee1e5e7eef (patch) | |
tree | b98c2c5a9af7d77d6a16c328540559e9d4ef81fc /lib | |
parent | 6161d60dde60dc690726e8c1501e5847c3a66ad9 (diff) | |
download | coreutils-9a067599377f27bdc0831c233c7eeeee1e5e7eef.tar.xz |
*** empty log message ***
Diffstat (limited to 'lib')
-rw-r--r-- | lib/dup2.c | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/lib/dup2.c b/lib/dup2.c new file mode 100644 index 000000000..32afed50f --- /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 +} |