xref: /third_party/toybox/toys/lsb/hostname.c (revision 0f66f451)
1/* hostname.c - Get/Set the hostname
2 *
3 * Copyright 2012 Andre Renaud <andre@bluewatersys.com>
4 *
5 * http://refspecs.linuxfoundation.org/LSB_4.1.0/LSB-Core-generic/LSB-Core-generic/hostname.html
6
7USE_HOSTNAME(NEWTOY(hostname, ">1bdsfF:[!bdsf]", TOYFLAG_BIN))
8USE_DNSDOMAINNAME(NEWTOY(dnsdomainname, ">0", TOYFLAG_BIN))
9
10config HOSTNAME
11  bool "hostname"
12  default y
13  help
14    usage: hostname [-bdsf] [-F FILENAME] [newname]
15
16    Get/set the current hostname.
17
18    -b	Set hostname to 'localhost' if otherwise unset
19    -d	Show DNS domain name (no host)
20    -f	Show fully-qualified name (host+domain, FQDN)
21    -F	Set hostname to contents of FILENAME
22    -s	Show short host name (no domain)
23
24config DNSDOMAINNAME
25  bool "dnsdomainname"
26  default y
27  help
28    usage: dnsdomainname
29
30    Show domain this system belongs to (same as hostname -d).
31*/
32
33#define FOR_hostname
34#define FORCE_FLAGS
35#include "toys.h"
36
37GLOBALS(
38  char *F;
39)
40
41void hostname_main(void)
42{
43  char *hostname = toybuf, *dot;
44  struct hostent *h;
45
46  gethostname(toybuf, sizeof(toybuf)-1);
47  if (TT.F && (hostname = xreadfile(TT.F, 0, 0))) {
48    if (!*chomp(hostname)) {
49      if (CFG_TOYBOX_FREE) free(hostname);
50      if (!FLAG(b)) error_exit("empty '%s'", TT.F);
51      hostname = 0;
52    }
53  } else hostname  = (FLAG(b) && !*toybuf) ? "localhost" : *toys.optargs;
54
55  // Setting?
56  if (hostname) {
57    if (sethostname(hostname, strlen(hostname)))
58      perror_exit("set '%s'", hostname);
59    return;
60  }
61
62  // We only do the DNS lookup for -d and -f.
63  if (FLAG(d) || FLAG(f)) {
64    if (!(h = gethostbyname(toybuf)))
65      error_exit("gethostbyname: %s", hstrerror(h_errno));
66    snprintf(toybuf, sizeof(toybuf), "%s", h->h_name);
67  }
68  dot = toybuf+strcspn(toybuf, ".");
69  if (FLAG(s)) *dot = '\0';
70  xputs(FLAG(d) ? dot+1 : toybuf);
71}
72
73void dnsdomainname_main(void)
74{
75  toys.optflags = FLAG_d;
76  hostname_main();
77}
78