From be0e9420a1673b7b3991d7eec843d75219a84f34 Mon Sep 17 00:00:00 2001 From: Guido van Rossum Date: Fri, 24 Dec 1993 10:32:00 +0000 Subject: New files. --- Python/dup2.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) create mode 100644 Python/dup2.c (limited to 'Python/dup2.c') diff --git a/Python/dup2.c b/Python/dup2.c new file mode 100644 index 0000000000..85ec5d5e5f --- /dev/null +++ b/Python/dup2.c @@ -0,0 +1,31 @@ +/* + * Public domain dup2() lookalike + * by Curtis Jackson @ AT&T Technologies, Burlington, NC + * electronic address: burl!rcj + * + * dup2 performs the following functions: + * + * Check to make sure that fd1 is a valid open file descriptor. + * Check to see if fd2 is already open; if so, close it. + * Duplicate fd1 onto fd2; checking to make sure fd2 is a valid fd. + * Return fd2 if all went well; return BADEXIT otherwise. + */ + +#include + +#define BADEXIT -1 + +int +dup2(fd1, fd2) +int fd1, fd2; +{ + if (fd1 != fd2) { + if (fcntl(fd1, F_GETFL) < 0) + return BADEXIT; + if (fcntl(fd2, F_GETFL) >= 0) + close(fd2); + if (fcntl(fd1, F_DUPFD, fd2) < 0) + return BADEXIT; + } + return fd2; +} -- cgit v1.2.1