LDP
/
man-pages
mirror of https://github.com/mkerrisk/man-pages
0
1
Fork 0
Code Releases Activity

freopen(3) can change file descriptor associations of stin/stdout/stderr

This commit is contained in:
Michael Kerrisk 2005-06-16 16:10:05 +00:00
parent b99cf1e0e8
commit 6a4c2e3618
1 changed files with 10 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
man3/stdin.3
View File

@ -2,6 +2,7 @@
.\"
.\" This man page was written in 1998 by David A. Holland
.\" and placed in the Public Domain. Polished a bit by aeb.
.\" 2005-06-16 mtk, mentioned freopen()
.\"
.Dd March 24, 1998
.Dt STDIN 3
@ -48,14 +49,21 @@ interface, that is, the functions like
.Xr read 2
and
.Xr lseek 2 .
The integer file descriptors associated with the streams
.Pp
On program startup, the integer file descriptors
associated with the streams
.Nm stdin ,
.Nm stdout ,
and
.Nm stderr
are 0, 1, and 2, respectively. The preprocessor symbols STDIN_FILENO,
are 0, 1, and 2, respectively.
The preprocessor symbols STDIN_FILENO,
STDOUT_FILENO, and STDERR_FILENO are defined with these values in
<unistd.h>.
(Applying
.Xr freopen 3
to one of these streams can change the file descriptor number
associated with the stream.)
.Pp
Note that mixing use of FILEs and raw file descriptors can produce
unexpected results and should generally be avoided.