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authorDenis Vlasenko <vda.linux@googlemail.com>2008-03-27 16:26:35 +0000
committerDenis Vlasenko <vda.linux@googlemail.com>2008-03-27 16:26:35 +0000
commit95891fc016c9911406cb826540873f0894bcbe8b (patch)
tree6bd21013d32cd589946742000c021ad95de61634 /console-tools/openvt.c
parent72b3442aeb948a9f27822d8888df765393b9ecd4 (diff)
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openvt: fix gross mismatch between us and "standard" openvt.
standard one even has different syntax! std: "openvt -c 12", we: "openvt 12" std: "openvt top", we: complain that "top" is not a number. openvt: implement -c -w -s (-l -f -v are also accepted but ingnored) openvt_main 188 343 +155 vfork_child - 67 +67 not_vt_fd - 23 +23 packed_usage 23932 23952 +20 ------------------------------------------------------------------------------ (add/remove: 2/0 grow/shrink: 2/0 up/down: 265/0) Total: 265 bytes text data bss dec hex filename 801344 641 7380 809365 c5995 busybox_old 801617 641 7380 809638 c5aa6 busybox_unstripped
Diffstat (limited to 'console-tools/openvt.c')
-rw-r--r--console-tools/openvt.c161
1 files changed, 148 insertions, 13 deletions
diff --git a/console-tools/openvt.c b/console-tools/openvt.c
index 39b985995..6f2aa19c4 100644
--- a/console-tools/openvt.c
+++ b/console-tools/openvt.c
@@ -8,29 +8,164 @@
8 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. 8 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
9 */ 9 */
10 10
11/* getopt not needed */ 11#include <linux/vt.h>
12
13#include "libbb.h" 12#include "libbb.h"
14 13
14/* "Standard" openvt's man page (we do not support all of this):
15
16openvt [-c NUM] [-fsulv] [--] [command [args]]
17
18Find the first available VT, and run command on it. Stdio is directed
19to that VT. If no command is specified then $SHELL is used.
20
21-c NUM
22 Use the given VT number, not the first free one.
23-f
24 Force opening a VT: don't try to check if VT is already in use.
25-s
26 Switch to the new VT when starting the command.
27 The VT of the new command will be made the new current VT.
28-u
29 Figure out the owner of the current VT, and run login as that user.
30 Suitable to be called by init. Shouldn't be used with -c or -l.
31-l
32 Make the command a login shell: a "-" is prepended to the argv[0]
33 when command is executed.
34-v
35 Verbose.
36-w
37 Wait for command to complete. If -w and -s are used together,
38 switch back to the controlling terminal when the command completes.
39
40bbox:
41-u: not implemented
42-f: always in effect
43-l: not implemented, ignored
44-v: ignored
45-ws: does NOT switch back
46*/
47
48/* Helper: does this fd understand VT_xxx? */
49static int not_vt_fd(int fd)
50{
51 struct vt_stat vtstat;
52 return ioctl(fd, VT_GETSTATE, &vtstat); /* !0: error, it's not VT fd */
53}
54
55/* Helper: get a fd suitable for VT_xxx */
56static int get_vt_fd(void)
57{
58 int fd;
59
60 /* Do we, by chance, already have it? */
61 for (fd = 0; fd < 3; fd++)
62 if (!not_vt_fd(fd))
63 return fd;
64 /* _only_ O_NONBLOCK: ask for neither read not write perms */
65 fd = open(DEV_CONSOLE, O_NONBLOCK);
66 if (fd >= 0 && !not_vt_fd(fd))
67 return fd;
68 bb_error_msg_and_die("can't find open VT");
69}
70
71static int find_free_vtno(void)
72{
73 int vtno;
74 int fd = get_vt_fd();
75
76 errno = 0;
77 /*xfunc_error_retval = 3; - do we need compat? */
78 if (ioctl(fd, VT_OPENQRY, &vtno) != 0 || vtno <= 0)
79 bb_perror_msg_and_die("can't find open VT");
80// Not really needed, grep for DAEMON_ONLY_SANITIZE
81// if (fd > 2)
82// close(fd);
83 return vtno;
84}
85
86/* vfork scares gcc, it generates bigger code.
87 * Keep it away from main program.
88 * TODO: move to libbb; or adapt existing libbb's spawn().
89 */
90static NOINLINE void vfork_child(char **argv)
91{
92 if (vfork() == 0) {
93 /* CHILD */
94 /* Try to make this VT our controlling tty */
95 setsid(); /* lose old ctty */
96 ioctl(0, TIOCSCTTY, 0 /* 0: don't forcibly steal */);
97 //bb_error_msg("our sid %d", getsid(0));
98 //bb_error_msg("our pgrp %d", getpgrp());
99 //bb_error_msg("VT's sid %d", tcgetsid(0));
100 //bb_error_msg("VT's pgrp %d", tcgetpgrp(0));
101 BB_EXECVP(argv[0], argv);
102 bb_perror_msg_and_die("exec %s", argv[0]);
103 }
104}
105
15int openvt_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; 106int openvt_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
16int openvt_main(int argc, char **argv) 107int openvt_main(int argc ATTRIBUTE_UNUSED, char **argv)
17{ 108{
18 char vtname[sizeof(VC_FORMAT) + 2]; 109 char vtname[sizeof(VC_FORMAT) + sizeof(int)*3];
110 char *str_c;
111 int vtno;
112 int flags;
113 enum {
114 OPT_c = (1 << 0),
115 OPT_w = (1 << 1),
116 OPT_s = (1 << 2),
117 OPT_l = (1 << 3),
118 OPT_f = (1 << 4),
119 OPT_v = (1 << 5),
120 };
19 121
20 if (argc < 3) 122 /* "+" - stop on first non-option */
21 bb_show_usage(); 123 flags = getopt32(argv, "+c:wslfv", &str_c);
124 argv += optind;
22 125
23 /* check for illegal vt number: < 1 or > 63 */ 126 if (flags & OPT_c) {
24 sprintf(vtname, VC_FORMAT, (int)xatou_range(argv[1], 1, 63)); 127 /* Check for illegal vt number: < 1 or > 63 */
128 vtno = xatou_range(str_c, 1, 63);
129 } else {
130 vtno = find_free_vtno();
131 }
25 132
26 bb_daemonize_or_rexec(DAEMON_CLOSE_EXTRA_FDS, argv); 133 /* Grab new VT */
27 /* grab new one */ 134 sprintf(vtname, VC_FORMAT, vtno);
135 /* (Try to) clean up stray open fds above fd 2 */
136 bb_daemonize_or_rexec(DAEMON_CLOSE_EXTRA_FDS | DAEMON_ONLY_SANITIZE, NULL);
28 close(0); 137 close(0);
138 /*setsid(); - BAD IDEA: after we exit, child is SIGHUPed... */
29 xopen(vtname, O_RDWR); 139 xopen(vtname, O_RDWR);
140
141 if (flags & OPT_s) {
142 xioctl(0, VT_ACTIVATE, (void*)(ptrdiff_t)vtno);
143 xioctl(0, VT_WAITACTIVE, (void*)(ptrdiff_t)vtno);
144 }
145
146 if (!argv[0]) {
147 argv--;
148 argv[0] = getenv("SHELL");
149 if (!argv[0])
150 argv[0] = (char *) DEFAULT_SHELL;
151 /*argv[1] = NULL; - already is */
152 }
153
30 xdup2(0, STDOUT_FILENO); 154 xdup2(0, STDOUT_FILENO);
31 xdup2(0, STDERR_FILENO); 155 xdup2(0, STDERR_FILENO);
32 156
33 argv += 2; 157#ifdef BLOAT
34 BB_EXECVP(argv[0], argv); 158 /* Handle -l (login shell) option */
35 _exit(1); 159 const char *prog = argv[0];
160 if (flags & OPT_l)
161 argv[0] = xasprintf("-%s", argv[0]);
162#endif
163
164 vfork_child(argv);
165 if (flags & OPT_w) {
166 wait(NULL);
167// TODO: -ws handling should be here
168 }
169
170 return EXIT_SUCCESS;
36} 171}
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