busybox/busybox.c
Mark Whitley 130005cd89 Applied patch from Gaute B Strokkenes <gs234@cam.ac.uk> to use a binary search
to locate applets, rather than a linear search. Also, broke out the listing of
applets into it's own file: applets.h.
2000-10-25 00:28:27 +00:00

210 lines
4.1 KiB
C

/* vi: set sw=4 ts=4: */
#include "busybox.h"
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include "applets.h"
#define bb_need_full_version
#define BB_DECLARE_EXTERN
#include "messages.c"
static int been_there_done_that = 0;
const char *applet_name;
#ifdef BB_FEATURE_INSTALLER
/*
* directory table
* this should be consistent w/ the enum, busybox.h::Location,
* or else...
*/
static char* install_dir[] = {
"/",
"/bin",
"/sbin",
"/usr/bin",
"/usr/sbin",
};
/* abstract link() */
typedef int (*__link_f)(const char *, const char *);
/*
* Where in the filesystem is this busybox?
* [return]
* malloc'd string w/ full pathname of busybox's location
* NULL on failure
*/
static char *busybox_fullpath()
{
pid_t pid;
char path[256];
char proc[256];
int len;
pid = getpid();
sprintf(proc, "/proc/%d/exe", pid);
len = readlink(proc, path, 256);
if (len != -1) {
path[len] = 0;
} else {
errorMsg("%s: %s\n", proc, strerror(errno));
return NULL;
}
return strdup(path);
}
/* create (sym)links for each applet */
static void install_links(const char *busybox, int use_symbolic_links)
{
__link_f Link = link;
char command[256];
int i;
int rc;
if (use_symbolic_links) Link = symlink;
for (i = 0; applets[i].name != NULL; i++) {
sprintf ( command, "%s/%s",
install_dir[applets[i].location],
applets[i].name);
rc = Link(busybox, command);
if (rc) {
errorMsg("%s: %s\n", command, strerror(errno));
}
}
}
#endif /* BB_FEATURE_INSTALLER */
int main(int argc, char **argv)
{
const char *s;
int u, l; /* Lower and upper bounds for the binary search. */
applet_name = "busybox";
#ifdef BB_FEATURE_INSTALLER
/*
* This style of argument parsing doesn't scale well
* in the event that busybox starts wanting more --options.
* If someone has a cleaner approach, by all means implement it.
*/
if (argc > 1 && (strcmp(argv[1], "--install") == 0)) {
int use_symbolic_links = 0;
int rc = 0;
char *busybox;
/* to use symlinks, or not to use symlinks... */
if (argc > 2) {
if ((strcmp(argv[2], "-s") == 0)) {
use_symbolic_links = 1;
}
}
/* link */
busybox = busybox_fullpath();
if (busybox) {
install_links(busybox, use_symbolic_links);
free(busybox);
} else {
rc = 1;
}
return rc;
}
#endif /* BB_FEATURE_INSTALLER */
for (s = applet_name = argv[0]; *s != '\0';) {
if (*s++ == '/')
applet_name = s;
}
*argv = (char*)applet_name;
#ifdef BB_SH
/* Add in a special case hack -- whenever **argv == '-'
* (i.e. '-su' or '-sh') always invoke the shell */
if (**argv == '-' && *(*argv+1)!= '-') {
exit(((*(shell_main)) (argc, argv)));
}
#endif
/* Do a binary search to find the applet entry given the name. */
u = NUM_APPLETS - 1;
l = 0;
for (;;) {
int i = l + (u - l) / 2;
int j = strcmp(applet_name, applets[i].name);
if (j == 0) {
if (applets[i].usage && argv[1] && strcmp(argv[1], "--help") == 0)
usage(applets[i].usage);
exit(((*(applets[i].main)) (argc, argv)));
}
if (u == l)
break;
if (j < 0)
u = i - 1;
else
l = i + 1;
if (u < l)
break;
}
return(busybox_main(argc, argv));
}
int busybox_main(int argc, char **argv)
{
int col = 0;
argc--;
argv++;
if (been_there_done_that == 1 || argc < 1) {
const struct BB_applet *a = applets;
fprintf(stderr, "%s\n\n"
"Usage: busybox [function] [arguments]...\n"
" or: [function] [arguments]...\n\n"
"\tBusyBox is a multi-call binary that combines many common Unix\n"
"\tutilities into a single executable. Most people will create a\n"
"\tlink to busybox for each function they wish to use, and BusyBox\n"
"\twill act like whatever it was invoked as.\n"
"\nCurrently defined functions:\n", full_version);
while (a->name != 0) {
col +=
fprintf(stderr, "%s%s", ((col == 0) ? "\t" : ", "),
(a++)->name);
if (col > 60 && a->name != 0) {
fprintf(stderr, ",\n");
col = 0;
}
}
fprintf(stderr, "\n\n");
exit(-1);
}
/* If we've already been here once, exit now */
been_there_done_that = 1;
return (main(argc, argv));
}
/*
Local Variables:
c-file-style: "linux"
c-basic-offset: 4
tab-width: 4
End:
*/