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

2024-12-21 07:30:05 +00:00 · 1997-07-27 23:15:09 +00:00 · 1997-07-27 23:15:09 +00:00 · 9b450f3e72
commit 9b450f3e72
parent c2791150e8
1 changed files with 154 additions and 0 deletions
--- a/lib/libc/stdio/fdopen.c
+++ b/lib/libc/stdio/fdopen.c
@ -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;
+}