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-rw-r--r--private/crt32/lowio/read.c349
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diff --git a/private/crt32/lowio/read.c b/private/crt32/lowio/read.c
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+/***
+*read.c - OS/2 read from a file handle
+*
+* Copyright (c) 1989-1993, Microsoft Corporation. All rights reserved.
+*
+*Purpose:
+* defines _read() - read from a file handle
+*
+*Revision History:
+* 06-19-89 PHG Module created, based on asm version
+* 03-13-90 GJF Made calling type _CALLTYPE2 (for now), added #include
+* <cruntime.h> and fixed compiler warnings. Also, fixed
+* the copyright.
+* 04-03-90 GJF Now _CALLTYPE1.
+* 07-24-90 SBM Removed '32' from API names
+* 08-14-90 SBM Compiles cleanly with -W3
+* 10-01-90 GJF New-style function declarator.
+* 12-04-90 GJF Appended Win32 version onto the source with #ifdef-s.
+* It is enough different that there is little point in
+* trying to more closely merge the two versions.
+* 12-04-90 SRW Changed to include <oscalls.h> instead of <doscalls.h>
+* 12-06-90 SRW Changed to use _osfile and _osfhnd instead of _osfinfo
+* 12-28-90 SRW Added cast of void * to char * for Mips C Compiler
+* 01-16-91 GJF ANSI naming.
+* 01-29-91 SRW Changed to not read ahead on char devices [_WIN32_]
+* 02-01-91 SRW Changed to use ERROR_HANDLE_EOF error code (_WIN32_)
+* 02-25-91 MHL Adapt to ReadFile/WriteFile changes (_WIN32_)
+* 04-09-91 PNT Added _MAC_ conditional
+* 04-16-91 SRW Character device bug fix [_WIN32_]
+* 05-23-91 GJF Don't set FEOFLAG if handle corresponds to a device.
+* 10-24-91 GJF Added LPDWORD casts to make MIPS compiler happy.
+* ASSUMES THAT sizeof(int) == sizeof(DWORD).
+* 02-13-92 GJF Replaced _nfile by _nhandle for Win32.
+* 06-16-92 GJF Bug fix - if CR was the very last char read, and the
+* last char in the file, CRLF was getting written to
+* user's buffer.
+* 12-18-93 GJF Don't treat ERROR_BROKEN_PIPE as an error. Instead,
+* just return 0.
+*
+*******************************************************************************/
+
+#include <cruntime.h>
+#include <oscalls.h>
+#include <os2dll.h>
+#include <io.h>
+#include <internal.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <msdos.h>
+
+#define LF 10 /* line feed */
+#define CR 13 /* carriage return */
+#define CTRLZ 26 /* ctrl-z means eof for text */
+
+/***
+*int _read(fh, buf, cnt) - read bytes from a file handle
+*
+*Purpose:
+* Attempts to read cnt bytes from fh into a buffer.
+* If the file is in text mode, CR-LF's are mapped to LF's, thus
+* affecting the number of characters read. This does not
+* affect the file pointer.
+*
+* NOTE: The stdio _IOCTRLZ flag is tied to the use of FEOFLAG.
+* Cross-reference the two symbols before changing FEOFLAG's use.
+*
+*Entry:
+* int fh - file handle to read from
+* char *buf - buffer to read into
+* int cnt - number of bytes to read
+*
+*Exit:
+* Returns number of bytes read (may be less than the number requested
+* if the EOF was reached or the file is in text mode).
+* returns -1 (and sets errno) if fails.
+*
+*Exceptions:
+*
+*******************************************************************************/
+
+#ifdef MTHREAD
+
+/* define normal version that locks/unlocks, validates fh */
+int _CALLTYPE1 _read (
+ int fh,
+ void *buf,
+ unsigned cnt
+ )
+{
+ int r; /* return value */
+
+ /* validate handle */
+#ifdef _WIN32_
+ if ( (unsigned)fh >= (unsigned)_nhandle ) {
+#else
+ if ((unsigned)fh >= (unsigned)_nfile) {
+#endif
+ /* out of range -- return error */
+ errno = EBADF;
+ _doserrno = 0; /* not OS/2 error */
+ return -1;
+ }
+
+ _lock_fh(fh); /* lock file */
+ r = _read_lk(fh, buf, cnt); /* read bytes */
+ _unlock_fh(fh); /* unlock file */
+
+ return r;
+}
+
+/* now define version that doesn't lock/unlock, validate fh */
+int _CALLTYPE1 _read_lk (
+ int fh,
+ void *buf,
+ unsigned cnt
+ )
+{
+ int bytes_read; /* number of bytes read */
+ char *buffer; /* buffer to read to */
+ int os_read; /* bytes read on OS call */
+ char *p, *q; /* pointers into buffer */
+ char peekchr; /* peek-ahead character */
+ ULONG filepos; /* file position after seek */
+ ULONG dosretval; /* OS/2 return value */
+
+
+#else
+
+/* now define normal version */
+int _CALLTYPE1 _read (
+ int fh,
+ void *buf,
+ unsigned cnt
+ )
+{
+ int bytes_read; /* number of bytes read */
+ char *buffer; /* buffer to read to */
+ int os_read; /* bytes read on OS call */
+ char *p, *q; /* pointers into buffer */
+ char peekchr; /* peek-ahead character */
+ ULONG filepos; /* file position after seek */
+ ULONG dosretval; /* OS/2 return value */
+
+ /* validate fh */
+#ifdef _WIN32_
+ if ( (unsigned)fh >= (unsigned)_nhandle ) {
+#else
+ if ((unsigned)fh >= (unsigned)_nfile) {
+#endif
+ /* bad file handle */
+ errno = EBADF;
+ _doserrno = 0; /* not OS/2 error */
+ return -1;
+ }
+
+#endif
+
+ bytes_read = 0; /* nothing read yet */
+ buffer = buf;
+
+ if (cnt == 0 || (_osfile[fh] & FEOFLAG)) {
+ /* nothing to read or at EOF, so return 0 read */
+ return 0;
+ }
+
+ if ((_osfile[fh] & (FPIPE|FDEV)) && _pipech[fh] != LF) {
+ /* a pipe/device and pipe lookahead non-empty: read the lookahead char */
+ *buffer++ = _pipech[fh];
+ ++bytes_read;
+ --cnt;
+ _pipech[fh] = LF; /* mark as empty */
+ }
+
+ /* read the data */
+#ifdef _CRUISER_
+
+ if ( dosretval = DOSREAD(fh, buffer, cnt, &os_read) ) {
+ /* OS error, map it and return */
+ if (dosretval == ERROR_ACCESS_DENIED) {
+ /* wrong read/write mode should return EBADF, not EACCES */
+ errno = EBADF;
+ _doserrno = dosretval;
+ }
+ else
+ _dosmaperr(dosretval);
+ return -1;
+ }
+
+#else /* ndef _CRUISER_ */
+
+#ifdef _WIN32_
+
+ if ( !ReadFile((HANDLE)_osfhnd[fh], buffer, cnt, (LPDWORD)&os_read,
+ NULL) ) {
+
+ /* ReadFile has reported an error. recognize two special cases.
+ *
+ * 1. map ERROR_ACCESS_DENIED to EBADF
+ *
+ * 2. just return 0 if ERROR_BROKEN_PIPE has occurred. it
+ * means the handle is a read-handle on a pipe for which
+ * all write-handles have been closed and all data has been
+ * read. */
+
+ if ( (dosretval = GetLastError()) == ERROR_ACCESS_DENIED ) {
+ /* wrong read/write mode should return EBADF, not EACCES */
+ errno = EBADF;
+ _doserrno = dosretval;
+ return -1;
+ }
+ else if ( dosretval == ERROR_BROKEN_PIPE ) {
+ return 0;
+ }
+ else {
+ _dosmaperr(dosretval);
+ return -1;
+ }
+ }
+
+#else /* ndef _WIN32_ */
+
+#ifdef _MAC_
+
+ TBD();
+
+#else /* ndef _MAC_ */
+
+#error ERROR - ONLY CRUISER, WIN32, OR MAC TARGET SUPPORTED!
+
+#endif /* _MAC_ */
+
+#endif /* _WIN32_ */
+
+#endif /* _CRUISER_ */
+
+ bytes_read += os_read; /* update bytes read */
+
+ if (_osfile[fh] & FTEXT) {
+ /* now must translate CR-LFs to LFs in the buffer */
+
+ /* set CRLF flag to indicate LF at beginning of buffer */
+ if (*(char *)buf == LF)
+ _osfile[fh] |= FCRLF;
+ else
+ _osfile[fh] &= ~FCRLF;
+
+ /* convert chars in the buffer: p is src, q is dest */
+ p = q = buf;
+ while (p < (char *)buf + bytes_read) {
+ if (*p == CTRLZ) {
+ /* if fh is not a device, set ctrl-z flag */
+ if ( !(_osfile[fh] & FDEV) )
+ _osfile[fh] |= FEOFLAG;
+ break; /* stop translating */
+ }
+ else if (*p != CR)
+ *q++ = *p++;
+ else {
+ /* *p is CR, so must check next char for LF */
+ if (p < (char *)buf + bytes_read - 1) {
+ if (*(p+1) == LF) {
+ p += 2;
+ *q++ = LF; /* convert CR-LF to LF */
+ }
+ else
+ *q++ = *p++; /* store char normally */
+ }
+ else {
+ /* This is the hard part. We found a CR at end of
+ buffer. We must peek ahead to see if next char
+ is an LF. */
+ ++p;
+#ifdef _CRUISER_
+
+ dosretval = DOSREAD(fh, &peekchr, 1, &os_read);
+
+#else /* ndef _CRUISER_ */
+
+#ifdef _WIN32_
+
+ dosretval = 0;
+ if ( !ReadFile((HANDLE)_osfhnd[fh], &peekchr, 1,
+ (LPDWORD)&os_read, NULL) )
+ dosretval = GetLastError();
+
+#else /* ndef _WIN32_ */
+
+#ifdef _MAC_
+
+ TBD();
+
+#else /* ndef _MAC_ */
+
+#error ERROR - ONLY CRUISER, WIN32, OR MAC TARGET SUPPORTED!
+
+#endif /* _MAC_ */
+
+#endif /* _WIN32_ */
+
+#endif /* _CRUISER_ */
+ if (dosretval != 0 || os_read == 0) {
+ /* couldn't read ahead, store CR */
+ *q++ = CR;
+ }
+ else {
+ /* peekchr now has the extra character -- we now have
+ several possibilities:
+ 1. disk file and char is not LF; just seek back
+ and copy CR
+ 2. disk file and char is LF; seek back and discard CR
+ 3. disk file, char is LF but this is a one-byte read:
+ store LF, don't seek back
+ 4. pipe/device and char is LF; store LF.
+ 5. pipe/device and char isn't LF, store CR and put
+ char in pipe lookahead buffer. */
+ if (_osfile[fh] & (FDEV|FPIPE)) {
+ /* non-seekable device */
+ if (peekchr == LF)
+ *q++ = LF;
+ else {
+ *q++ = CR;
+ _pipech[fh] = peekchr;
+ }
+ }
+ else {
+ /* disk file */
+ if (q == buf && peekchr == LF) {
+ /* nothing read yet; must make some progress */
+ *q++ = LF;
+ }
+ else {
+ /* seek back */
+ filepos = _lseek_lk(fh, -1, FILE_CURRENT);
+ if (peekchr != LF)
+ *q++ = CR;
+ }
+ }
+ }
+ }
+ }
+ }
+
+ /* we now change bytes_read to reflect the true number of chars
+ in the buffer */
+ bytes_read = q - (char *)buf;
+ }
+
+ return bytes_read; /* and return */
+}
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