aboutsummaryrefslogtreecommitdiff
path: root/toys/other
diff options
context:
space:
mode:
Diffstat (limited to 'toys/other')
-rw-r--r--toys/other/sysctl.c152
1 files changed, 152 insertions, 0 deletions
diff --git a/toys/other/sysctl.c b/toys/other/sysctl.c
new file mode 100644
index 00000000..8e57ca1d
--- /dev/null
+++ b/toys/other/sysctl.c
@@ -0,0 +1,152 @@
+/* sysctl.c - A utility to read and manipulate the sysctl parameters.
+ *
+ * Copyright 2014 Bilal Qureshi <bilal.jmi@gmail.com>
+ * Copyright 2014 Kyungwan Han <asura321@gmail.com>
+ *
+ * No Standard
+
+USE_SYSCTL(NEWTOY(sysctl, "^neNqwpaA[!ap][!aq][!aw][+aA]", TOYFLAG_USR|TOYFLAG_BIN))
+
+config SYSCTL
+ bool "sysctl"
+ default y
+ help
+ usage: sysctl [-aAeNnqw] [-p [FILE] | KEY[=VALUE]...]
+
+ Read/write system control data (under /proc/sys).
+
+ -a,A Show all values
+ -e Don't warn about unknown keys
+ -N Don't print key values
+ -n Don't print key names
+ -p [FILE] Read values from FILE (default /etc/sysctl.conf)
+ -q Don't show value after write
+ -w Only write values (object to reading)
+*/
+#define FOR_sysctl
+#include "toys.h"
+
+// Null terminate at =, return value
+static char *split_key(char *key)
+{
+ char *value = strchr(key, '=');
+
+ if (value) *(value++)=0;
+
+ return value;
+}
+
+static void replace_char(char *str, char old, char new)
+{
+ for (; *str; str++) if (*str == old) *str = new;
+}
+
+static void key_error(char *key)
+{
+ if (errno == ENOENT) {
+ if (!(toys.optflags & FLAG_e)) error_msg("unknown key '%s'", key);
+ } else perror_msg("key '%s'", key);
+}
+
+static int write_key(char *path, char *key, char *value)
+{
+ int fd = open(path, O_WRONLY);;
+
+ if (fd < 0) {
+ key_error(key);
+
+ return 0;
+ }
+ xwrite(fd, value, strlen(value));
+ xclose(fd);
+
+ return 1;
+}
+
+// Display all keys under a path
+static int do_show_keys(struct dirtree *dt)
+{
+ char *path, *data, *key;
+
+ if (!dirtree_notdotdot(dt)) return 0; // Skip . and ..
+ if (S_ISDIR(dt->st.st_mode)) return DIRTREE_RECURSE;
+
+ path = dirtree_path(dt, 0);
+ data = readfile(path, 0, 0);
+ replace_char(key = path + 10, '/', '.'); // skip "/proc/sys/"
+ if (!data) key_error(key);
+ else {
+ // Print the parts that aren't switched off by flags.
+ if (!(toys.optflags & FLAG_n)) xprintf("%s", key);
+ if (!(toys.optflags & (FLAG_N|FLAG_n))) xprintf(" = ");
+ for (key = data+strlen(data); key > data && isspace(*--key); *key = 0);
+ if (!(toys.optflags & FLAG_N)) xprintf("%s", data);
+ if ((toys.optflags & (FLAG_N|FLAG_n)) != (FLAG_N|FLAG_n)) xputc('\n');
+ }
+
+ free(data);
+ free(path);
+
+ return 0;
+}
+
+// Read/write entries under a key. Accepts "key=value" in key if !value
+static void process_key(char *key, char *value)
+{
+ char *path;
+
+ if (!value) value = split_key(key);
+ if ((toys.optflags & FLAG_w) && !value) {
+ error_msg("'%s' not key=value");
+
+ return;
+ }
+
+ path = xmprintf("/proc/sys/%s", key);
+ replace_char(path, '.', '/');
+ // Note: failure to assign to a non-leaf node suppresses the display.
+ if (!(value && (!write_key(path, key, value) || (toys.optflags & FLAG_q)))) {
+ if (!access(path, R_OK)) dirtree_read(path, do_show_keys);
+ else key_error(key);
+ }
+ free(path);
+}
+
+void sysctl_main()
+{
+ char **args = 0;
+
+ // Display all keys
+ if (toys.optflags & FLAG_a) dirtree_read("/proc/sys", do_show_keys);
+
+ // read file
+ else if (toys.optflags & FLAG_p) {
+ FILE *fp = xfopen(*toys.optargs ? *toys.optargs : "/etc/sysctl.conf", "r");
+ size_t len;
+
+ for (;;) {
+ char *line = 0, *key, *val;
+
+ if (-1 == (len = getline(&line, &len, fp))) break;
+ key = line;
+ while (isspace(*key)) key++;
+ if (*key == '#' || *key == ';' || !*key) continue;
+ while (len && isspace(line[len-1])) line[--len] = 0;
+ if (!(val = split_key(line))) {
+ error_msg("'%s' not key=value", line);
+ continue;
+ }
+
+ // Trim whitespace around =
+ len = (val-line)-1;
+ while (len && isspace(line[len-1])) line[--len] = 0;
+ while (isspace(*val)) val++;;
+
+ process_key(key, val);
+ free(line);
+ }
+ fclose(fp);
+
+ // Loop through arguments, displaying or assigning as appropriate
+ } else for (args = toys.optargs; *args; args++) process_key(*args, 0);
+}