tools:iio:iio_utils: pass strings as const

Mark strings, which are not supposed to be changed (basedir, filename,
value), as const in function parameters.

Signed-off-by: Hartmut Knaack <[e-mail]>
Signed-off-by: Jonathan Cameron <[e-mail]>

tools/iio/iio_utils.c

···
 	return ret;
 }
 
-static int _write_sysfs_int(char *filename, char *basedir, int val, int verify)
+static int _write_sysfs_int(const char *filename, const char *basedir, int val,
+			    int verify)
 {
 	int ret = 0;
 	FILE *sysfsfp;
···
  *
  * Returns a value >= 0 on success, otherwise a negative error code.
  **/
-int write_sysfs_int(char *filename, char *basedir, int val)
+int write_sysfs_int(const char *filename, const char *basedir, int val)
 {
 	return _write_sysfs_int(filename, basedir, val, 0);
 }
···
  *
  * Returns a value >= 0 on success, otherwise a negative error code.
  **/
-int write_sysfs_int_and_verify(char *filename, char *basedir, int val)
+int write_sysfs_int_and_verify(const char *filename, const char *basedir,
+			       int val)
 {
 	return _write_sysfs_int(filename, basedir, val, 1);
 }
 
-static int _write_sysfs_string(char *filename, char *basedir, char *val,
-			       int verify)
+static int _write_sysfs_string(const char *filename, const char *basedir,
+			       const char *val, int verify)
 {
 	int ret = 0;
 	FILE  *sysfsfp;
···
  *
  * Returns a value >= 0 on success, otherwise a negative error code.
  **/
-int write_sysfs_string_and_verify(char *filename, char *basedir, char *val)
+int write_sysfs_string_and_verify(const char *filename, const char *basedir,
+				  const char *val)
 {
 	return _write_sysfs_string(filename, basedir, val, 1);
 }
···
  *
  * Returns a value >= 0 on success, otherwise a negative error code.
  **/
-int write_sysfs_string(char *filename, char *basedir, char *val)
+int write_sysfs_string(const char *filename, const char *basedir,
+		       const char *val)
 {
 	return _write_sysfs_string(filename, basedir, val, 0);
 }
···
  * Returns the read integer value >= 0 on success, otherwise a negative error
  * code.
  **/
-int read_sysfs_posint(char *filename, char *basedir)
+int read_sysfs_posint(const char *filename, const char *basedir)
 {
 	int ret;
 	FILE  *sysfsfp;
···
  *
  * Returns a value >= 0 on success, otherwise a negative error code.
  **/
-int read_sysfs_float(char *filename, char *basedir, float *val)
+int read_sysfs_float(const char *filename, const char *basedir, float *val)
 {
 	int ret = 0;
 	FILE  *sysfsfp;

tools/iio/iio_utils.h

···
 int build_channel_array(const char *device_dir,
 						struct iio_channel_info **ci_array, int *counter);
 int find_type_by_name(const char *name, const char *type);
-int write_sysfs_int(char *filename, char *basedir, int val);
-int write_sysfs_int_and_verify(char *filename, char *basedir, int val);
-int write_sysfs_string_and_verify(char *filename, char *basedir, char *val);
-int write_sysfs_string(char *filename, char *basedir, char *val);
-int read_sysfs_posint(char *filename, char *basedir);
-int read_sysfs_float(char *filename, char *basedir, float *val);
+int write_sysfs_int(const char *filename, const char *basedir, int val);
+int write_sysfs_int_and_verify(const char *filename, const char *basedir,
+			       int val);
+int write_sysfs_string_and_verify(const char *filename, const char *basedir,
+				  const char *val);
+int write_sysfs_string(const char *filename, const char *basedir,
+		       const char *val);
+int read_sysfs_posint(const char *filename, const char *basedir);
+int read_sysfs_float(const char *filename, const char *basedir, float *val);
 int read_sysfs_string(const char *filename, const char *basedir, char *str);
 
 #endif /* _IIO_UTILS_H_ */