aboutsummaryrefslogtreecommitdiff
path: root/src/xz/file_io.c
diff options
context:
space:
mode:
authorLasse Collin <lasse.collin@tukaani.org>2010-01-24 22:46:11 +0200
committerLasse Collin <lasse.collin@tukaani.org>2010-01-24 22:46:11 +0200
commitdf254ce03be016e217b511e7acd5d493f9929ca5 (patch)
tree8f4b899baead57de436606aa37b0bd139909402f /src/xz/file_io.c
parentSet LC_NUMERIC=C when --robot is used. (diff)
downloadxz-df254ce03be016e217b511e7acd5d493f9929ca5.tar.xz
Add io_pread().
It will be used by --list.
Diffstat (limited to 'src/xz/file_io.c')
-rw-r--r--src/xz/file_io.c25
1 files changed, 25 insertions, 0 deletions
diff --git a/src/xz/file_io.c b/src/xz/file_io.c
index d94e2321..a07501c1 100644
--- a/src/xz/file_io.c
+++ b/src/xz/file_io.c
@@ -812,6 +812,31 @@ io_read(file_pair *pair, io_buf *buf_union, size_t size)
}
+extern bool
+io_pread(file_pair *pair, io_buf *buf, size_t size, off_t pos)
+{
+ // Using lseek() and read() is more portable than pread() and
+ // for us it is as good as real pread().
+ if (lseek(pair->src_fd, pos, SEEK_SET) != pos) {
+ message_error(_("%s: Error seeking the file: %s"),
+ pair->src_name, strerror(errno));
+ return true;
+ }
+
+ const size_t amount = io_read(pair, buf, size);
+ if (amount == SIZE_MAX)
+ return true;
+
+ if (amount != size) {
+ message_error(_("%s: Unexpected end of file"),
+ pair->src_name);
+ return true;
+ }
+
+ return false;
+}
+
+
static bool
is_sparse(const io_buf *buf)
{