First cleanup pass on sysctl.

Remove unnecessary typecasting of things that are already char * to char *,
and multiplying by sizeof(char *) which is 1. Rename do_process() do_flag_a()
since that's the only caller. Move read_key_values() down past trim_spaces()
and read_config_file() so it's next to its only two users. Replace some
euphemisms for 0 with 0.

replace_char() really sounds like something libc should already have one of,
but I'm blanking on it if so. (It doesn't need a temporary variable when the
argument variable is already a copy so changing it won't affect the caller.)

diff --git a/toys/pending/sysctl.c b/toys/pending/sysctl.c
index 74e7dee..7e8736d 100644 (file)
--- a/toys/pending/sysctl.c
+++ b/toys/pending/sysctl.c
@@ -13,6 +13,8 @@ config SYSCTL
   help
     usage: sysctl [OPTIONS] [KEY[=VALUE]]...
 
+    Configure kernel parameters at runtime.
+
     -a, A      Show all values
     -e         Don't warn about unknown keys
     -N         Show only key names
@@ -45,10 +47,7 @@ show_error_msg:
 
 static void replace_char(char *str, char old, char new)
 {
-  char *tmp = str;
-
-  for (; *tmp; tmp++) 
-    if (*tmp == old) *tmp = new;
+  for (; *str; str++) if (*str == old) *str = new;
 }
 
 static void handle_file_error(char *key_name)
@@ -84,11 +83,11 @@ static void write_to_file(char *fpath, char *key_name, char *key_value)
 
 static char *get_key_value(char *buff, int *offset)
 {
-  char *line, *tmp = (char *) (buff + *offset);
+  char *line, *tmp = buff + *offset;
   int index = 0, multiplier = 1;
 
-  if (!(*tmp)) return NULL;
-  line = (char *) xmalloc(sizeof(char) * MAX_BYTES_LINE);
+  if (!*tmp) return 0;
+  line = xmalloc(MAX_BYTES_LINE);
   for (; *tmp != '\n'; tmp++) {
     line[index++] = *tmp;
     if (MAX_BYTES_LINE == index) { // buffer overflow
@@ -101,35 +100,6 @@ static char *get_key_value(char *buff, int *offset)
   return line;
 }
 
-// Open file for each and every key name and read file contents
-void read_key_values(char *fpath)
-{
-  char *key_value, *fdata, *key_name, *tmp = xstrdup(fpath);
-  int offset = 0;
-
-  key_name = (tmp + strlen(PROC_SYS_DIR) + 1);
-  replace_char(key_name, '/', '.');
-  if (!(fdata = readfile(fpath, NULL, 0))) {
-    handle_file_error(key_name);
-    free(tmp);
-    return;
-  }
-  if (toys.optflags & FLAG_N) {
-    xprintf("%s\n", key_name);
-    free(tmp);
-    free(fdata);
-    return;
-  }
-  for (; (key_value = get_key_value(fdata, &offset)); free(key_value)) {
-    if (!(toys.optflags & FLAG_q)) {
-      if (!(toys.optflags & FLAG_n)) xprintf("%s = ", key_name);
-      xprintf("%s\n", key_value);
-    }
-  }
-  free(tmp);
-  free(fdata);
-}
-
 static void trim_spaces(char **param)
 {
   int len = 0;
@@ -147,7 +117,7 @@ static void trim_spaces(char **param)
   }
 }
 
-// Read config file and write values to there corresponding key name files
+// Read config file and write values to corresponding key name files
 static void read_config_file(char *fname)
 {
   char *line, *name = NULL, *value = NULL;
@@ -167,7 +137,36 @@ static void read_config_file(char *fname)
   xclose(fd);
 }
 
-static int do_process(struct dirtree *dt)
+// Open file for each and every key name and read file contents
+void read_key_values(char *fpath)
+{
+  char *key_value, *fdata, *key_name, *tmp = xstrdup(fpath);
+  int offset = 0;
+
+  key_name = (tmp + strlen(PROC_SYS_DIR) + 1);
+  replace_char(key_name, '/', '.');
+  if (!(fdata = readfile(fpath, NULL, 0))) {
+    handle_file_error(key_name);
+    free(tmp);
+    return;
+  }
+  if (toys.optflags & FLAG_N) {
+    xprintf("%s\n", key_name);
+    free(tmp);
+    free(fdata);
+    return;
+  }
+  for (; (key_value = get_key_value(fdata, &offset)); free(key_value)) {
+    if (!(toys.optflags & FLAG_q)) {
+      if (!(toys.optflags & FLAG_n)) xprintf("%s = ", key_name);
+      xprintf("%s\n", key_value);
+    }
+  }
+  free(tmp);
+  free(fdata);
+}
+
+static int do_flag_a(struct dirtree *dt)
 {
   char *fpath;
 
@@ -177,15 +176,16 @@ static int do_process(struct dirtree *dt)
     read_key_values(fpath);
     free(fpath);
   }
+
   return 0;
 }
 
 void sysctl_main()
 {
-  char *name = NULL, *value = NULL, **args = NULL;
+  char *name = 0, *value = 0, **args = 0;
 
   if (toys.optflags & FLAG_a) {
-    dirtree_read(PROC_SYS_DIR, do_process);
+    dirtree_read(PROC_SYS_DIR, do_flag_a);
     return;
   }
   if (toys.optflags & FLAG_p) {