applets/busybox.c

   1 /* vi: set sw=4 ts=4: */
   2 #include "busybox.h"
   3 #include <stdio.h>
   4 #include <string.h>
   5 #include <errno.h>
   6 #include "applets.h"
   7
   8 #define bb_need_full_version
   9 #define BB_DECLARE_EXTERN
  10 #include "messages.c"
  11
  12 static int been_there_done_that = 0;
  13
  14
  15 const char *applet_name;
  16
  17 #ifdef BB_FEATURE_INSTALLER
  18 /*
  19  * directory table
  20  *              this should be consistent w/ the enum, busybox.h::Location,
  21  *              or else...
  22  */
  23 static char* install_dir[] = {
  24         "/",
  25         "/bin",
  26         "/sbin",
  27         "/usr/bin",
  28         "/usr/sbin",
  29 };
  30
  31 /* abstract link() */
  32 typedef int (*__link_f)(const char *, const char *);
  33
  34 /*
  35  * Where in the filesystem is this busybox?
  36  * [return]
  37  *              malloc'd string w/ full pathname of busybox's location
  38  *              NULL on failure
  39  */
  40 static char *busybox_fullpath()
  41 {
  42         pid_t pid;
  43         char path[256];
  44         char proc[256];
  45         int len;
  46
  47         pid = getpid();
  48         sprintf(proc, "/proc/%d/exe", pid);
  49         len = readlink(proc, path, 256);
  50         if (len != -1) {
  51                 path[len] = 0;
  52         } else {
  53                 errorMsg("%s: %s\n", proc, strerror(errno));
  54                 return NULL;
  55         }
  56         return strdup(path);
  57 }
  58
  59 /* create (sym)links for each applet */
  60 static void install_links(const char *busybox, int use_symbolic_links)
  61 {
  62         __link_f Link = link;
  63
  64         char command[256];
  65         int i;
  66         int rc;
  67
  68         if (use_symbolic_links) Link = symlink;
  69
  70         for (i = 0; applets[i].name != NULL; i++) {
  71                 sprintf ( command, "%s/%s",
  72                                 install_dir[applets[i].location],
  73                                 applets[i].name);
  74                 rc = Link(busybox, command);
  75
  76                 if (rc) {
  77                         errorMsg("%s: %s\n", command, strerror(errno));
  78                 }
  79         }
  80 }
  81
  82 #endif /* BB_FEATURE_INSTALLER */
  83
  84 static int applet_name_compare(const void *x, const void *y)
  85 {
  86         const struct BB_applet *applet1 = x;
  87         const struct BB_applet *applet2 = y;
  88
  89         return strcmp(applet1->name, applet2->name);
  90 }
  91
  92 int main(int argc, char **argv)
  93 {
  94         struct BB_applet search_applet, *applet;
  95         const char                              *s;
  96         applet_name = "busybox";
  97
  98 #ifdef BB_FEATURE_INSTALLER
  99         /*
 100          * This style of argument parsing doesn't scale well
 101          * in the event that busybox starts wanting more --options.
 102          * If someone has a cleaner approach, by all means implement it.
 103          */
 104         if (argc > 1 && (strcmp(argv[1], "--install") == 0)) {
 105                 int use_symbolic_links = 0;
 106                 int rc = 0;
 107                 char *busybox;
 108
 109                 /* to use symlinks, or not to use symlinks... */
 110                 if (argc > 2) {
 111                         if ((strcmp(argv[2], "-s") == 0)) {
 112                                 use_symbolic_links = 1;
 113                         }
 114                 }
 115
 116                 /* link */
 117                 busybox = busybox_fullpath();
 118                 if (busybox) {
 119                         install_links(busybox, use_symbolic_links);
 120                         free(busybox);
 121                 } else {
 122                         rc = 1;
 123                 }
 124                 return rc;
 125         }
 126 #endif /* BB_FEATURE_INSTALLER */
 127
 128         for (s = applet_name = argv[0]; *s != '\0';) {
 129                 if (*s++ == '/')
 130                         applet_name = s;
 131         }
 132
 133         *argv = (char*)applet_name;
 134
 135 #ifdef BB_SH
 136         /* Add in a special case hack -- whenever **argv == '-'
 137          * (i.e. '-su' or '-sh') always invoke the shell */
 138         if (**argv == '-' && *(*argv+1)!= '-') {
 139                 exit(((*(shell_main)) (argc, argv)));
 140         }
 141 #endif
 142
 143         /* Do a binary search to find the applet entry given the name. */
 144         search_applet.name = applet_name;
 145         applet = bsearch(&search_applet, applets, NUM_APPLETS,
 146                         sizeof(struct BB_applet), applet_name_compare);
 147         if (applet != NULL) {
 148                 if (applet->usage && argv[1] && strcmp(argv[1], "--help") == 0)
 149                         usage(applet->usage);
 150                 exit((*(applet->main)) (argc, argv));
 151         }
 152
 153         return(busybox_main(argc, argv));
 154 }
 155
 156
 157 int busybox_main(int argc, char **argv)
 158 {
 159         int col = 0;
 160
 161         argc--;
 162         argv++;
 163
 164         if (been_there_done_that == 1 || argc < 1) {
 165                 const struct BB_applet *a = applets;
 166
 167                 fprintf(stderr, "%s\n\n"
 168                                 "Usage: busybox [function] [arguments]...\n"
 169                                 "   or: [function] [arguments]...\n\n"
 170                                 "\tBusyBox is a multi-call binary that combines many common Unix\n"
 171                                 "\tutilities into a single executable.  Most people will create a\n"
 172                                 "\tlink to busybox for each function they wish to use, and BusyBox\n"
 173                                 "\twill act like whatever it was invoked as.\n"
 174                                 "\nCurrently defined functions:\n", full_version);
 175
 176                 while (a->name != 0) {
 177                         col +=
 178                                 fprintf(stderr, "%s%s", ((col == 0) ? "\t" : ", "),
 179                                                 (a++)->name);
 180                         if (col > 60 && a->name != 0) {
 181                                 fprintf(stderr, ",\n");
 182                                 col = 0;
 183                         }
 184                 }
 185                 fprintf(stderr, "\n\n");
 186                 exit(-1);
 187         }
 188         /* If we've already been here once, exit now */
 189         been_there_done_that = 1;
 190         return (main(argc, argv));
 191 }
 192
 193 /*
 194 Local Variables:
 195 c-file-style: "linux"
 196 c-basic-offset: 4
 197 tab-width: 4
 198 End:
 199 */