chore: reduce debt for args

src/args.c

@@ -71,17 +71,17 @@ static void print_help(int status_code) {
   exit(status_code);
 }
 
-static void invalid_arg(char *arg) {
+static void invalid_arg(const char *arg) {
   log_error("invalid argument: '%s'", arg);
   print_help(EXIT_FAILURE);
 }
 
-static void invalid_value(char *arg, char *value) {
+static void invalid_value(const char *arg, const char *value) {
   log_error("invalid value for argument '%s': '%s'", arg, value);
   print_help(EXIT_FAILURE);
 }
 
-static bool is_arg(char *arg, const char *ref) {
+static bool is_arg(const char *arg, const char *ref) {
   return strcoll(arg, ref) == 0;
 }
 
@@ -93,7 +93,7 @@ static char *split_arg_value(char *arg) {
   return rest;
 }
 
-static unsigned int parse_uint(char *arg, char *value) {
+static unsigned int parse_uint(const char *arg, const char *value) {
   unsigned long long tmp_value;
 
   if (!string_is_number(value)) {

src/string.c

@@ -39,7 +39,7 @@ unsigned int string_trim(char *str) {
 
 static bool is_digit(char c) { return c >= '0' && c <= '9'; }
 
-bool string_is_number(char *value) {
+bool string_is_number(const char *value) {
   unsigned long value_len;
 
   if (value == NULL) {
@@ -57,8 +57,8 @@ bool string_is_number(char *value) {
   return true;
 }
 
-char *string_replace_at(char *src, unsigned int from, unsigned int to,
+char *string_replace_at(const char *src, unsigned int from, unsigned int to,
-                        char *rpl) {
+                        const char *rpl) {
   unsigned long src_len, rpl_len;
   char *dst;
 

src/string.h

@@ -5,9 +5,9 @@
 
 unsigned int string_trim(char *str);
 
-bool string_is_number(char *value);
+bool string_is_number(const char *value);
 
-char *string_replace_at(char *src, unsigned int from, unsigned int to,
+char *string_replace_at(const char *src, unsigned int from, unsigned int to,
-                        char *rpl);
+                        const char *rpl);
 
 #endif /* STRINGS_H */