[libvirt] [PATCH v3 01/14] util: implement virFileReadOffsetQuiet()
Implement virFileReadOffsetQuiet() that reads a given maximum number
of bytes into a buffer that will be allocated. The reading starts
from a given offset.
Signed-off-by: Stefan Berger <stefanb(a)linux.vnet.ibm.com>
---
src/libvirt_private.syms | 1 +
src/util/virfile.c | 14 +++++++++++++-
src/util/virfile.h | 3 +++
3 files changed, 17 insertions(+), 1 deletion(-)
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 92b5e0f..f2a4921 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -1807,6 +1807,7 @@ virFileReadHeaderFD;
virFileReadHeaderQuiet;
virFileReadLimFD;
virFileReadLink;
+virFileReadOffsetQuiet;
virFileReadValueBitmap;
virFileReadValueInt;
virFileReadValueScaledInt;
diff --git a/src/util/virfile.c b/src/util/virfile.c
index 40f106d..526b9ad 100644
--- a/src/util/virfile.c
+++ b/src/util/virfile.c
@@ -1432,12 +1432,18 @@ virFileReadAll(const char *path, int maxlen, char **buf)
}
int
-virFileReadAllQuiet(const char *path, int maxlen, char **buf)
+virFileReadOffsetQuiet(const char *path, off_t offset,
+ int maxlen, char **buf)
{
int fd = open(path, O_RDONLY);
if (fd < 0)
return -errno;
+ if (offset > 0 && lseek(fd, offset, SEEK_SET) < 0) {
+ VIR_FORCE_CLOSE(fd);
+ return -errno;
+ }
+
int len = virFileReadLimFD(fd, maxlen, buf);
VIR_FORCE_CLOSE(fd);
if (len < 0)
@@ -1446,6 +1452,12 @@ virFileReadAllQuiet(const char *path, int maxlen, char **buf)
return len;
}
+int
+virFileReadAllQuiet(const char *path, int maxlen, char **buf)
+{
+ return virFileReadOffsetQuiet(path, 0, maxlen, buf);
+}
+
/* Read @file into preallocated buffer @buf of size @len.
* Return value is -errno in case of errors and size
* of data read (no trailing zero) in case of success.
diff --git a/src/util/virfile.h b/src/util/virfile.h
index 341320b..13d3cf6 100644
--- a/src/util/virfile.h
+++ b/src/util/virfile.h
@@ -137,6 +137,9 @@ int virFileReadLimFD(int fd, int maxlen, char **buf)
ATTRIBUTE_RETURN_CHECK ATTRIBUTE_NONNULL(3);
int virFileReadAll(const char *path, int maxlen, char **buf)
ATTRIBUTE_RETURN_CHECK ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(3);
+int virFileReadOffsetQuiet(const char *path, off_t offset,
+ int maxlen, char **buf)
+ ATTRIBUTE_RETURN_CHECK ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(4);
int virFileReadAllQuiet(const char *path, int maxlen, char **buf)
ATTRIBUTE_RETURN_CHECK ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(3);
int virFileReadBufQuiet(const char *file, char *buf, int len)
--
2.5.5