source: MondoRescue/branches/stable/mindi-busybox/applets/busybox.c@ 821

/* vi: set sw=4 ts=4: */
/*
 * BusyBox' main applet dispatcher.
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */
#include "busybox.h"
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <stdlib.h>
#if ENABLE_LOCALE_SUPPORT
#include <locale.h>
#else
#define setlocale(x,y)
#endif

const char *bb_applet_name ATTRIBUTE_EXTERNALLY_VISIBLE;

#ifdef CONFIG_FEATURE_INSTALLER
/*
 * directory table
 *      this should be consistent w/ the enum, busybox.h::Location,
 *      or else...
 */
static const char usr_bin [] ="/usr/bin";
static const char usr_sbin[] ="/usr/sbin";

static const char* const install_dir[] = {
    &usr_bin [8], /* "", equivalent to "/" for concat_path_file() */
    &usr_bin [4], /* "/bin" */
    &usr_sbin[4], /* "/sbin" */
    usr_bin,
    usr_sbin
};

/* abstract link() */
typedef int (*__link_f)(const char *, const char *);

/* create (sym)links for each applet */
static void install_links(const char *busybox, int use_symbolic_links)
{
    __link_f Link = link;

    char *fpc;
    int i;
    int rc;

    if (use_symbolic_links)
        Link = symlink;

    for (i = 0; applets[i].name != NULL; i++) {
        fpc = concat_path_file(
            install_dir[applets[i].location], applets[i].name);
        rc = Link(busybox, fpc);
        if (rc!=0 && errno!=EEXIST) {
            bb_perror_msg("%s", fpc);
        }
        free(fpc);
    }
}

#else
#define install_links(x,y)
#endif /* CONFIG_FEATURE_INSTALLER */

int main(int argc, char **argv)
{
    const char *s;

    bb_applet_name=argv[0];
    if (*bb_applet_name == '-') bb_applet_name++;
    for (s = bb_applet_name; *s ;)
        if (*(s++) == '/') bb_applet_name = s;

    /* Set locale for everybody except `init' */
    if(ENABLE_LOCALE_SUPPORT && getpid() != 1)
        setlocale(LC_ALL, "");

    run_applet_by_name(bb_applet_name, argc, argv);
    bb_error_msg_and_die("applet not found");
}

int busybox_main(int argc, char **argv)
{
    /*
     * 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 (ENABLE_FEATURE_INSTALLER && argc > 1 && !strcmp(argv[1], "--install")) {
        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 = xreadlink("/proc/self/exe");
        if (busybox) {
            install_links(busybox, use_symbolic_links);
            free(busybox);
        } else {
            rc = 1;
        }
        return rc;
    }

    /* Deal with --help.  (Also print help when called with no arguments) */

    if (argc==1 || !strcmp(argv[1],"--help") ) {
        if (argc>2) {
            run_applet_by_name(bb_applet_name=argv[2], 2, argv);
        } else {
            const struct BB_applet *a;
            int col, output_width;

            if (ENABLE_FEATURE_AUTOWIDTH) {
                /* Obtain the terminal width.  */
                get_terminal_width_height(0, &output_width, NULL);
                /* leading tab and room to wrap */
                output_width -= 20;
            } else output_width = 60;

            printf("%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", bb_msg_full_version);

            col=0;
            for(a = applets; a->name;) {
                col += printf("%s%s", (col ? ", " : "\t"), (a++)->name);
                if (col > output_width && a->name) {
                    printf(",\n");
                    col = 0;
                }
            }
            printf("\n\n");
            exit(0);
        }
    } else run_applet_by_name(argv[1], argc-1, argv+1);

    bb_error_msg_and_die("applet not found");
}