diff options
Diffstat (limited to 'private/crt32/stdio/fdopen.c')
| -rw-r--r-- | private/crt32/stdio/fdopen.c | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/private/crt32/stdio/fdopen.c b/private/crt32/stdio/fdopen.c new file mode 100644 index 000000000..25681f257 --- /dev/null +++ b/private/crt32/stdio/fdopen.c @@ -0,0 +1,191 @@ +/*** +*fdopen.c - open a file descriptor as stream +* +* Copyright (c) 1985-1992, Microsoft Corporation. All rights reserved. +* +*Purpose: +* defines _fdopen() - opens a file descriptor as a stream, thus allowing +* buffering, etc. +* +*Revision History: +* 09-02-83 RN initial version +* 03-02-87 JCR added support for 'b' and 't' embedded in mode strings +* 09-28-87 JCR Corrected _iob2 indexing (now uses _iob_index() macro). +* 11-03-87 JCR Multi-thread support +* 12-11-87 JCR Added "_LOAD_DS" to declaration +* 05-31-88 PHG Merged DLL and normal versions +* 06-06-88 JCR Optimized _iob2 references +* 11-20-89 GJF Fixed copyright, indents. Added const to type of mode. +* 02-15-90 GJF _iob[], _iob2[] merge. +* 03-16-90 GJF Replaced _LOAD_DS with _CALLTYPE1, added #include +* <cruntime.h> and removed #include <register.h>. +* 07-23-90 SBM Replaced <assertm.h> by <assert.h> +* 08-24-90 SBM Added support for 'c' and 'n' flags +* 10-02-90 GJF New-style function declarator. +* 01-21-91 GJF ANSI naming. +* 02-14-92 GJF Replaced _nfile with _nhandle for Win32. +* 05-01-92 DJM Replaced _nfile with OPEN_MAX for POSIX. +* 08-03-92 GJF Function name must be "fdopen" for POSIX. +* +*******************************************************************************/ + +#include <cruntime.h> +#include <stdio.h> +#include <file2.h> +#include <assert.h> +#include <internal.h> +#include <os2dll.h> +#ifdef _POSIX_ +#include <limits.h> +#endif + +/*** +*FILE *_fdopen(filedes, mode) - open a file descriptor as a stream +* +*Purpose: +* associates a stream with a file handle, thus allowing buffering, etc. +* The mode must be specified and must be compatible with the mode +* the file was opened with in the low level open. +* +*Entry: +* int filedes - handle referring to open file +* char *mode - file mode to use ("r", "w", "a", etc.) +* +*Exit: +* returns stream pointer and sets FILE struct fields if successful +* returns NULL if fails +* +*Exceptions: +* +*******************************************************************************/ + +#ifdef _POSIX_ +FILE * _CALLTYPE1 fdopen ( +#else +FILE * _CALLTYPE1 _fdopen ( +#endif + int filedes, + REG2 const char *mode + ) +{ + REG1 FILE *stream; + int whileflag, tbflag, cnflag; +#ifdef MTHREAD + int index; +#endif + + assert(mode != NULL); + +#ifdef _WIN32_ + assert(filedes < _nhandle); + + if ( (unsigned)filedes >= (unsigned)_nhandle ) + return(NULL); +#else + +#ifdef _POSIX_ + assert(filedes < OPEN_MAX); + + if (filedes < 0 || filedes >= OPEN_MAX) + return(NULL); +#else + assert(filedes < _nfile); + + if (filedes < 0 || filedes >= _nfile) + return(NULL); + +#endif /* _POSIX_ */ + +#endif /* _WIN32_ */ + + + /* Find a free stream; stream is returned 'locked'. */ + + if ((stream = _getstream()) == NULL) + return(NULL); + +#ifdef MTHREAD + index = _iob_index(stream); +#endif + + /* First character must be 'r', 'w', or 'a'. */ + + switch (*mode) { + case 'r': + stream->_flag = _IOREAD; + break; + case 'w': + case 'a': + stream->_flag = _IOWRT; + break; + default: + stream = NULL; /* error */ + goto done; + break; + } + + /* There can be up to three more optional characters: + (1) A single '+' character, + (2) One of 'b' and 't' and + (3) One of 'c' and 'n'. + + Note that currently, the 't' and 'b' flags are syntax checked + but ignored. 'c' and 'n', however, are correctly supported. + */ + + whileflag=1; + tbflag=cnflag=0; + stream->_flag |= _commode; + + while(*++mode && whileflag) + switch(*mode) { + + case '+': + if (stream->_flag & _IORW) + whileflag=0; + else { + stream->_flag |= _IORW; + stream->_flag &= ~(_IOREAD | _IOWRT); + } + break; + + case 'b': + case 't': + if (tbflag) + whileflag=0; + else + tbflag=1; + break; + + case 'c': + if (cnflag) + whileflag = 0; + else { + cnflag = 1; + stream->_flag |= _IOCOMMIT; + } + break; + + case 'n': + if (cnflag) + whileflag = 0; + else { + cnflag = 1; + stream->_flag &= ~_IOCOMMIT; + } + break; + + default: + whileflag=0; + break; + } + + _cflush++; /* force library pre-termination procedure */ + stream->_file = filedes; + +/* Common return */ + +done: + _unlock_str(index); + return(stream); +} |