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Added an fdopen(3) implementation. It's not yet working quite right.

This commit is contained in:
gdr 1997-07-27 23:15:09 +00:00
parent c2791150e8
commit 9b450f3e72

154
lib/libc/stdio/fdopen.c Normal file
View File

@ -0,0 +1,154 @@
/*
* fdopen(3) implementation.
*
* Devin Reade, April 1997
*
* This file is formatted with tab stops every 8 columns
*
* $Id: fdopen.c,v 1.1 1997/07/27 23:15:09 gdr Exp $
*/
#ifdef __ORCAC__
segment "libc_stdio";
#endif
#pragma optimize 0
#pragma debug 0
#pragma memorymodel 0
#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
FILE *
fdopen(int fildes, const char *cmode)
{
FILE *result;
struct stat *statbuf;
unsigned int mode, whence, isBinary;
/* allocate buffers */
if ((statbuf = malloc(sizeof(struct stat))) == NULL) {
goto fail1;
}
if ((result = malloc(sizeof(FILE))) == NULL) {
goto fail2;
}
if ((result->_base = malloc(BUFSIZ)) == NULL) {
goto fail3;
}
/* stat the file descriptor */
if ((fstat(fildes, statbuf)) == -1) {
goto fail4;
}
/* extract the mode */
result->_flag = _IOFBF | _IOMYBUF;
mode = 0;
whence = SEEK_SET;
isBinary = 0;
switch(*cmode) {
case 'r':
mode = _IOREAD;
break;
case 'a':
whence = SEEK_END;
/*FALLTHROUGH*/
case 'w':
mode = _IOWRT;
break;
default:
errno = EINVAL;
goto fail4;
}
cmode++;
switch (*cmode) {
case 0:
break;
case 'b':
isBinary = 1;
cmode++;
switch(*cmode) {
case 0:
break;
case '+':
mode = _IORW;
break;
default:
errno = EINVAL;
goto fail4;
}
case '+':
mode = _IORW;
/*
* We don't document this behavior, but we will allow
* the 'b' to come in the third position as well, since
* it appears that this is the case for the ORCA fopen
* implementation.
*/
cmode++;
if (*cmode == 'b') {
isBinary = 1;
}
break;
default:
errno = EINVAL;
goto fail4;
}
if (!isBinary) {
result->_flag |= _IOTEXT;
}
result->_flag |= mode;
/*
* There is a bug in the beta v2.0.6 kernel that, when stat'ing
* a character special device, only the S_IFCHR bit is set. A
* similar situation is occuring for pipes/sockets.
*/
if (S_ISSOCK(statbuf->st_mode) || S_ISCHR(statbuf->st_mode)) {
goto pass;
}
/* verify that the req mode agrees with the file descriptor mode */
if ((result->_flag & (_IORW | _IOWRT)) &&
!(statbuf->st_mode & S_IWUSR)) {
errno = EPERM;
goto fail4;
}
if ((result->_flag & (_IORW | _IOREAD)) &&
!(statbuf->st_mode & S_IRUSR)) {
errno = EPERM;
goto fail4;
}
if (lseek(fildes, 0L, whence) == -1) {
if (errno != ENOTBLK) {
goto fail4;
}
}
/* set up remaining FILE struct members */
pass:
result->next = stderr->next;
stderr->next = result;
result->_ptr = result->_base;
result->_end = NULL;
result->_size = BUFSIZ;
result->_cnt = 0L;
result->_pbk[0] = -1;
result->_pbk[1] = -1;
result->_file = fildes;
return result;
fail4:
free(result->_base);
fail3:
free(result);
fail2:
free(statbuf);
fail1:
return NULL;
}