libfile: move open_and_lseek() to libfile

libfile is a collection of helpers for handling files. open_and_lseek()
is a perfect match for this, so move it there.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

commands/md.c

@@ -28,6 +28,7 @@
 #include <malloc.h>
 #include <errno.h>
 #include <fs.h>
+#include <libfile.h>
 #include <fcntl.h>
 #include <getopt.h>
 #include <linux/stat.h>

commands/mem.c

@@ -41,29 +41,6 @@
 
 char *mem_rw_buf;
 
-int open_and_lseek(const char *filename, int mode, loff_t pos)
-{
-	int fd, ret;
-
-	fd = open(filename, mode | O_RDONLY);
-	if (fd < 0) {
-		perror("open");
-		return fd;
-	}
-
-	if (!pos)
-		return fd;
-
-	ret = lseek(fd, pos, SEEK_SET);
-	if (ret == -1) {
-		perror("lseek");
-		close(fd);
-		return -errno;
-	}
-
-	return fd;
-}
-
 /*
  * Common function for parsing options for the 'md', 'mw', 'memcpy', 'memcmp'
  * commands.

commands/memcmp.c

@@ -28,6 +28,7 @@
 #include <malloc.h>
 #include <errno.h>
 #include <fs.h>
+#include <libfile.h>
 #include <fcntl.h>
 #include <getopt.h>
 #include <linux/stat.h>

commands/memcpy.c

@@ -28,6 +28,7 @@
 #include <malloc.h>
 #include <errno.h>
 #include <fs.h>
+#include <libfile.h>
 #include <fcntl.h>
 #include <getopt.h>
 #include <linux/stat.h>

commands/memset.c

@@ -28,6 +28,7 @@
 #include <malloc.h>
 #include <errno.h>
 #include <fs.h>
+#include <libfile.h>
 #include <fcntl.h>
 #include <getopt.h>
 #include <linux/stat.h>

commands/mm.c

@@ -22,6 +22,7 @@
 #include <malloc.h>
 #include <errno.h>
 #include <fs.h>
+#include <libfile.h>
 #include <fcntl.h>
 #include <getopt.h>
 #include <linux/stat.h>

commands/mw.c

@@ -28,6 +28,7 @@
 #include <malloc.h>
 #include <errno.h>
 #include <fs.h>
+#include <libfile.h>
 #include <fcntl.h>
 #include <getopt.h>
 #include <linux/stat.h>

include/common.h

@@ -128,7 +128,6 @@ static inline void print_hex_dump(const char *level, const char *prefix_str,
 
 int mem_parse_options(int argc, char *argv[], char *optstr, int *mode,
 		char **sourcefile, char **destfile, int *swab);
-int open_and_lseek(const char *filename, int mode, loff_t pos);
 #define RW_BUF_SIZE	(unsigned)4096
 
 extern const char version_string[];

include/libfile.h

@@ -19,4 +19,6 @@ int copy_recursive(const char *src, const char *dst);
 
 int compare_file(const char *f1, const char *f2);
 
+int open_and_lseek(const char *filename, int mode, loff_t pos);
+
 #endif /* __LIBFILE_H */

lib/libfile.c

@@ -442,3 +442,35 @@ err_out1:
 	close(fd1);
 	return ret;
 }
+
+/**
+ * open_and_lseek - open file and lseek to position
+ * @filename:	The file to open
+ * @mode:	The file open mode
+ * @pos:	The position to lseek to
+ *
+ * Return: If successful this function returns a positive filedescriptor
+ *         number, otherwise a negative error code is returned
+ */
+int open_and_lseek(const char *filename, int mode, loff_t pos)
+{
+	int fd, ret;
+
+	fd = open(filename, mode | O_RDONLY);
+	if (fd < 0) {
+		perror("open");
+		return fd;
+	}
+
+	if (!pos)
+		return fd;
+
+	ret = lseek(fd, pos, SEEK_SET);
+	if (ret == -1) {
+		perror("lseek");
+		close(fd);
+		return -errno;
+	}
+
+	return fd;
+}