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author | Roland McGrath <roland@gnu.org> | 1995-02-18 01:27:10 +0000 |
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committer | Roland McGrath <roland@gnu.org> | 1995-02-18 01:27:10 +0000 |
commit | 28f540f45bbacd939bfd07f213bcad2bf730b1bf (patch) | |
tree | 15f07c4c43d635959c6afee96bde71fb1b3614ee /sysdeps/posix/stdio_init.c | |
download | glibc-28f540f45bbacd939bfd07f213bcad2bf730b1bf.zip glibc-28f540f45bbacd939bfd07f213bcad2bf730b1bf.tar.gz glibc-28f540f45bbacd939bfd07f213bcad2bf730b1bf.tar.bz2 |
initial import
Diffstat (limited to 'sysdeps/posix/stdio_init.c')
-rw-r--r-- | sysdeps/posix/stdio_init.c | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/sysdeps/posix/stdio_init.c b/sysdeps/posix/stdio_init.c new file mode 100644 index 0000000..422d9b6 --- /dev/null +++ b/sysdeps/posix/stdio_init.c @@ -0,0 +1,70 @@ +/* Copyright (C) 1991, 1992, 1993, 1995 Free Software Foundation, Inc. +This file is part of the GNU C Library. + +The GNU C Library is free software; you can redistribute it and/or +modify it under the terms of the GNU Library General Public License as +published by the Free Software Foundation; either version 2 of the +License, or (at your option) any later version. + +The GNU C Library 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 +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +#include <ansidecl.h> +#include <stdio.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <unistd.h> + +/* Initialize STREAM as necessary. + This may change I/O functions, give a buffer, etc. + If no buffer is allocated, but the bufsize is set, + the bufsize will be used to allocate the buffer. */ +void +DEFUN(__stdio_init_stream, (stream), FILE *stream) +{ + register CONST int fd = (int) stream->__cookie; + struct stat statb; + + if (stream->__buffer != NULL || stream->__userbuf) + /* If's unbuffered by request, we can't do anything useful. */ + return; + + /* Find out what sort of file this is. */ + if (__fstat (fd, &statb) < 0) + return; + + if (S_ISCHR (statb.st_mode)) + { + /* It's a character device. + Make it line-buffered if it's a terminal. */ + if (__isatty (fd)) + { + stream->__linebuf = 1; + + /* Unix terminal devices have the bad habit of claiming to be + seekable. On systems I have tried, seeking on a terminal + device seems to set its file position as specified, such that + a later tell says the same thing. This is in no way related + to actual seekability--the ability to seek back and read old + data. Unix terminal devices will let you "seek back", and + then read more new data from the terminal. I can think of + nothing to do about this lossage except to preemptively disable + seeking on terminal devices. */ + + stream->__io_funcs.__seek = NULL; /* Seeks get ESPIPE. */ + } + } + +#ifdef _STATBUF_ST_BLKSIZE + /* Use the block-size field to determine + the system's optimal buffering size. */ + stream->__bufsize = statb.st_blksize; +#endif +} |