Mercurial > hg > octave-kai > gnulib-hg
changeset 291:b70199568782
.
author | Jim Meyering <jim@meyering.net> |
---|---|
date | Fri, 19 Aug 1994 13:13:48 +0000 |
parents | adaf7155fb9e |
children | 5c85c33d8ffa |
files | lib/ftruncate.c |
diffstat | 1 files changed, 51 insertions(+), 13 deletions(-) [+] |
line wrap: on
line diff
--- a/lib/ftruncate.c +++ b/lib/ftruncate.c @@ -1,10 +1,27 @@ /* ftruncate emulations that work on some System V's. - This file is in the public domain. */ + This file is in the public domain. */ + +#ifdef HAVE_CONFIG_H +#if defined (CONFIG_BROKETS) +/* We use <config.h> instead of "config.h" so that a compilation + using -I. -I$srcdir will use ./config.h rather than $srcdir/config.h + (which it would do because it found this file in $srcdir). */ +#include <config.h> +#else +#include "config.h" +#endif +#endif #include <sys/types.h> #include <fcntl.h> +#include <errno.h> +#ifndef STDC_HEADERS +extern int errno; +#endif + #ifdef F_CHSIZE + int ftruncate (fd, length) int fd; @@ -12,14 +29,17 @@ { return fcntl (fd, F_CHSIZE, length); } -#else + +#else /* not F_CHSIZE */ #ifdef F_FREESP -/* The following function was written by - kucharsk@Solbourne.com (William Kucharski) */ + +/* By William Kucharski <kucharsk@netcom.com>. */ #include <sys/stat.h> -#include <errno.h> + +#ifdef HAVE_UNISTD_H #include <unistd.h> +#endif int ftruncate (fd, length) @@ -44,23 +64,28 @@ } else { + /* Truncate length. */ + fl.l_whence = 0; fl.l_len = 0; fl.l_start = length; - fl.l_type = F_WRLCK; /* Write lock on file space. */ + fl.l_type = F_WRLCK; /* write lock on file space */ - /* This relies on the UNDOCUMENTED F_FREESP argument to - fcntl, which truncates the file so that it ends at the - position indicated by fl.l_start. - Will minor miracles never cease? */ + /* This relies on the *undocumented* F_FREESP argument to fcntl, + which truncates the file so that it ends at the position + indicated by fl.l_start. Will minor miracles never cease? */ + if (fcntl (fd, F_FREESP, &fl) < 0) return -1; } return 0; } -#else + +#else /* not F_CHSIZE nor F_FREESP */ +#ifdef HAVE_CHSIZE + int ftruncate (fd, length) int fd; @@ -68,5 +93,18 @@ { return chsize (fd, length); } -#endif -#endif + +#else /* not F_CHSIZE nor F_FREESP nor HAVE_CHSIZE */ + +int +ftruncate (fd, length) + int fd; + off_t length; +{ + errno = EIO; + return -1; +} + +#endif /* not HAVE_CHSIZE */ +#endif /* not F_FREESP */ +#endif /* not F_CHSIZE */