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comparison toys/other/sysctl.c @ 1285:1a8108bda4c1 draft

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Promote sysctl from pending to other, default y.
author Rob Landley <rob@landley.net>
date Thu, 15 May 2014 05:34:08 -0500
parents toys/pending/sysctl.c@5c1bd5b94541
children 58d9f1b61f0a
comparison
equal deleted inserted replaced
1284:5c1bd5b94541 1285:1a8108bda4c1
1 /* sysctl.c - A utility to read and manipulate the sysctl parameters.
2 *
3 * Copyright 2014 Bilal Qureshi <bilal.jmi@gmail.com>
4 * Copyright 2014 Kyungwan Han <asura321@gmail.com>
5 *
6 * No Standard
7
8 USE_SYSCTL(NEWTOY(sysctl, "^neNqwpaA[!ap][!aq][!aw][+aA]", TOYFLAG_USR|TOYFLAG_BIN))
9
10 config SYSCTL
11 bool "sysctl"
12 default y
13 help
14 usage: sysctl [-aAeNnqw] [-p [FILE] | KEY[=VALUE]...]
15
16 Read/write system control data (under /proc/sys).
17
18 -a,A Show all values
19 -e Don't warn about unknown keys
20 -N Don't print key values
21 -n Don't print key names
22 -p [FILE] Read values from FILE (default /etc/sysctl.conf)
23 -q Don't show value after write
24 -w Only write values (object to reading)
25 */
26 #define FOR_sysctl
27 #include "toys.h"
28
29 // Null terminate at =, return value
30 static char *split_key(char *key)
31 {
32 char *value = strchr(key, '=');
33
34 if (value) *(value++)=0;
35
36 return value;
37 }
38
39 static void replace_char(char *str, char old, char new)
40 {
41 for (; *str; str++) if (*str == old) *str = new;
42 }
43
44 static void key_error(char *key)
45 {
46 if (errno == ENOENT) {
47 if (!(toys.optflags & FLAG_e)) error_msg("unknown key '%s'", key);
48 } else perror_msg("key '%s'", key);
49 }
50
51 static int write_key(char *path, char *key, char *value)
52 {
53 int fd = open(path, O_WRONLY);;
54
55 if (fd < 0) {
56 key_error(key);
57
58 return 0;
59 }
60 xwrite(fd, value, strlen(value));
61 xclose(fd);
62
63 return 1;
64 }
65
66 // Display all keys under a path
67 static int do_show_keys(struct dirtree *dt)
68 {
69 char *path, *data, *key;
70
71 if (!dirtree_notdotdot(dt)) return 0; // Skip . and ..
72 if (S_ISDIR(dt->st.st_mode)) return DIRTREE_RECURSE;
73
74 path = dirtree_path(dt, 0);
75 data = readfile(path, 0, 0);
76 replace_char(key = path + 10, '/', '.'); // skip "/proc/sys/"
77 if (!data) key_error(key);
78 else {
79 // Print the parts that aren't switched off by flags.
80 if (!(toys.optflags & FLAG_n)) xprintf("%s", key);
81 if (!(toys.optflags & (FLAG_N|FLAG_n))) xprintf(" = ");
82 for (key = data+strlen(data); key > data && isspace(*--key); *key = 0);
83 if (!(toys.optflags & FLAG_N)) xprintf("%s", data);
84 if ((toys.optflags & (FLAG_N|FLAG_n)) != (FLAG_N|FLAG_n)) xputc('\n');
85 }
86
87 free(data);
88 free(path);
89
90 return 0;
91 }
92
93 // Read/write entries under a key. Accepts "key=value" in key if !value
94 static void process_key(char *key, char *value)
95 {
96 char *path;
97
98 if (!value) value = split_key(key);
99 if ((toys.optflags & FLAG_w) && !value) {
100 error_msg("'%s' not key=value");
101
102 return;
103 }
104
105 path = xmprintf("/proc/sys/%s", key);
106 replace_char(path, '.', '/');
107 // Note: failure to assign to a non-leaf node suppresses the display.
108 if (!(value && (!write_key(path, key, value) || (toys.optflags & FLAG_q)))) {
109 if (!access(path, R_OK)) dirtree_read(path, do_show_keys);
110 else key_error(key);
111 }
112 free(path);
113 }
114
115 void sysctl_main()
116 {
117 char **args = 0;
118
119 // Display all keys
120 if (toys.optflags & FLAG_a) dirtree_read("/proc/sys", do_show_keys);
121
122 // read file
123 else if (toys.optflags & FLAG_p) {
124 FILE *fp = xfopen(*toys.optargs ? *toys.optargs : "/etc/sysctl.conf", "r");
125 size_t len;
126
127 for (;;) {
128 char *line = 0, *key, *val;
129
130 if (-1 == (len = getline(&line, &len, fp))) break;
131 key = line;
132 while (isspace(*key)) key++;
133 if (*key == '#' || *key == ';' || !*key) continue;
134 while (len && isspace(line[len-1])) line[--len] = 0;
135 if (!(val = split_key(line))) {
136 error_msg("'%s' not key=value", line);
137 continue;
138 }
139
140 // Trim whitespace around =
141 len = (val-line)-1;
142 while (len && isspace(line[len-1])) line[--len] = 0;
143 while (isspace(*val)) val++;;
144
145 process_key(key, val);
146 free(line);
147 }
148 fclose(fp);
149
150 // Loop through arguments, displaying or assigning as appropriate
151 } else for (args = toys.optargs; *args; args++) process_key(*args, 0);
152 }