From: Paul Eggert Date: Wed, 8 Jan 2003 18:42:38 +0000 (+0000) Subject: import from gnulib X-Git-Url: https://git.brokenzipper.com/gitweb?a=commitdiff_plain;h=7154feb583181bba66f168bd1006bf812bd12b45;p=chaz%2Ftar import from gnulib --- diff --git a/lib/full-write.c b/lib/full-write.c index 4e566f6..1513705 100644 --- a/lib/full-write.c +++ b/lib/full-write.c @@ -1,7 +1,6 @@ -/* full-write.c -- an interface to write that retries after interrupts +/* An interface to read and write that retries (if necessary) until complete. - Copyright 1993, 1994, 1997, 1998, 1999, 2000, 2001 Free Software - Foundation, Inc. + Copyright (C) 1993, 1994, 1997-2003 Free Software Foundation, Inc. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -15,20 +14,17 @@ You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, - Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. - - Written by Paul Eggert. */ + Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #if HAVE_CONFIG_H # include #endif -#include - -#include "full-write.h" - -#if HAVE_UNISTD_H -# include +/* Specification. */ +#ifdef FULL_READ +# include "full-read.h" +#else +# include "full-write.h" #endif #include @@ -36,32 +32,54 @@ extern int errno; #endif -/* Write LEN bytes at PTR to descriptor DESC, retrying if interrupted - or if partial writes occur. Return the number of bytes successfully - written, setting errno if that is less than LEN. */ +#ifdef FULL_READ +# include "safe-read.h" +# define safe_rw safe_read +# define full_rw full_read +# undef const +# define const /* empty */ +#else +# include "safe-write.h" +# define safe_rw safe_write +# define full_rw full_write +#endif + +#ifdef FULL_READ +/* Set errno to zero upon EOF. */ +# define ZERO_BYTE_TRANSFER_ERRNO 0 +#else +/* Some buggy drivers return 0 when one tries to write beyond + a device's end. (Example: Linux 1.2.13 on /dev/fd0.) + Set errno to ENOSPC so they get a sensible diagnostic. */ +# define ZERO_BYTE_TRANSFER_ERRNO ENOSPC +#endif +/* Write(read) COUNT bytes at BUF to(from) descriptor FD, retrying if + interrupted or if a partial write(read) occurs. Return the number + of bytes transferred. + When writing, set errno if fewer than COUNT bytes are written. + When reading, if fewer than COUNT bytes are read, you must examine + errno to distinguish failure from EOF (errno == 0). */ size_t -full_write (int desc, const char *ptr, size_t len) +full_rw (int fd, const void *buf, size_t count) { - size_t total_written = 0; + size_t total = 0; + const char *ptr = buf; - while (len > 0) + while (count > 0) { - ssize_t written = write (desc, ptr, len); - if (written <= 0) + size_t n_rw = safe_rw (fd, ptr, count); + if (n_rw == (size_t) -1) + break; + if (n_rw == 0) { - /* Some buggy drivers return 0 when you fall off a device's end. */ - if (written == 0) - errno = ENOSPC; -#ifdef EINTR - if (errno == EINTR) - continue; -#endif + errno = ZERO_BYTE_TRANSFER_ERRNO; break; } - total_written += written; - ptr += written; - len -= written; + total += n_rw; + ptr += n_rw; + count -= n_rw; } - return total_written; + + return total; }