Denis Vlasenko | ac7d0e3 | 2007-10-08 19:32:12 +0000 | [diff] [blame] | 1 | /* vi: set sw=4 ts=4: */ |
| 2 | /* |
| 3 | * Support for main() which needs to end up in libbusybox, not busybox, |
| 4 | * if one builds libbusybox. |
| 5 | * |
| 6 | * Copyright (C) 2007 Denys Vlasenko <vda.linux@googlemail.com> |
| 7 | * |
| 8 | * Licensed under GPLv2, see file License in this tarball for details. |
| 9 | */ |
| 10 | |
| 11 | #include <assert.h> |
| 12 | #include "busybox.h" |
| 13 | |
| 14 | |
| 15 | /* Declare <applet>_main() */ |
| 16 | #define PROTOTYPES |
| 17 | #include "applets.h" |
| 18 | #undef PROTOTYPES |
| 19 | |
| 20 | #if ENABLE_SHOW_USAGE && !ENABLE_FEATURE_COMPRESS_USAGE |
| 21 | /* Define usage_messages[] */ |
| 22 | static const char usage_messages[] ALIGN1 = "" |
| 23 | #define MAKE_USAGE |
| 24 | #include "usage.h" |
| 25 | #include "applets.h" |
| 26 | ; |
| 27 | #undef MAKE_USAGE |
| 28 | #else |
| 29 | #define usage_messages 0 |
| 30 | #endif /* SHOW_USAGE */ |
| 31 | |
| 32 | /* Define struct bb_applet applets[] */ |
| 33 | #include "applets.h" |
| 34 | |
| 35 | #if ENABLE_FEATURE_SH_STANDALONE |
| 36 | /* -1 because last entry is NULL */ |
| 37 | const unsigned short NUM_APPLETS = ARRAY_SIZE(applets) - 1; |
| 38 | #endif |
| 39 | |
| 40 | |
| 41 | #if ENABLE_FEATURE_COMPRESS_USAGE |
| 42 | |
| 43 | #include "usage_compressed.h" |
| 44 | #include "unarchive.h" |
| 45 | |
| 46 | static const char *unpack_usage_messages(void) |
| 47 | { |
| 48 | char *outbuf = NULL; |
| 49 | bunzip_data *bd; |
| 50 | int i; |
| 51 | |
| 52 | i = start_bunzip(&bd, |
| 53 | /* src_fd: */ -1, |
| 54 | /* inbuf: */ packed_usage, |
| 55 | /* len: */ sizeof(packed_usage)); |
| 56 | /* read_bunzip can longjmp to start_bunzip, and ultimately |
| 57 | * end up here with i != 0 on read data errors! Not trivial */ |
| 58 | if (!i) { |
| 59 | /* Cannot use xmalloc: will leak bd in NOFORK case! */ |
| 60 | outbuf = malloc_or_warn(SIZEOF_usage_messages); |
| 61 | if (outbuf) |
| 62 | read_bunzip(bd, outbuf, SIZEOF_usage_messages); |
| 63 | } |
| 64 | dealloc_bunzip(bd); |
| 65 | return outbuf; |
| 66 | } |
| 67 | #define dealloc_usage_messages(s) free(s) |
| 68 | |
| 69 | #else |
| 70 | |
| 71 | #define unpack_usage_messages() usage_messages |
| 72 | #define dealloc_usage_messages(s) ((void)(s)) |
| 73 | |
| 74 | #endif /* FEATURE_COMPRESS_USAGE */ |
| 75 | |
| 76 | |
| 77 | void bb_show_usage(void) |
| 78 | { |
| 79 | if (ENABLE_SHOW_USAGE) { |
| 80 | const char *format_string; |
| 81 | const char *p; |
| 82 | const char *usage_string = p = unpack_usage_messages(); |
| 83 | const struct bb_applet *ap = find_applet_by_name(applet_name); |
| 84 | int i; |
| 85 | |
| 86 | if (!ap) /* never happens, paranoia */ |
| 87 | xfunc_die(); |
| 88 | |
| 89 | i = ap - applets; |
| 90 | while (i) { |
| 91 | while (*p++) continue; |
| 92 | i--; |
| 93 | } |
| 94 | |
| 95 | fprintf(stderr, "%s multi-call binary\n", bb_banner); |
| 96 | format_string = "\nUsage: %s %s\n\n"; |
| 97 | if (*p == '\b') |
| 98 | format_string = "\nNo help available.\n\n"; |
| 99 | fprintf(stderr, format_string, applet_name, p); |
| 100 | dealloc_usage_messages((char*)usage_string); |
| 101 | } |
| 102 | xfunc_die(); |
| 103 | } |
| 104 | |
| 105 | |
| 106 | static int applet_name_compare(const void *name, const void *vapplet) |
| 107 | { |
| 108 | const struct bb_applet *applet = vapplet; |
| 109 | |
| 110 | return strcmp(name, applet->name); |
| 111 | } |
| 112 | |
| 113 | const struct bb_applet *find_applet_by_name(const char *name) |
| 114 | { |
| 115 | /* Do a binary search to find the applet entry given the name. */ |
| 116 | return bsearch(name, applets, ARRAY_SIZE(applets)-1, sizeof(applets[0]), |
| 117 | applet_name_compare); |
| 118 | } |
| 119 | |
| 120 | |
| 121 | #ifdef __GLIBC__ |
| 122 | /* Make it reside in R/W memory: */ |
| 123 | int *const bb_errno __attribute__ ((section (".data"))); |
| 124 | #endif |
| 125 | |
| 126 | void bbox_prepare_main(char **argv) |
| 127 | { |
| 128 | #ifdef __GLIBC__ |
| 129 | (*(int **)&bb_errno) = __errno_location(); |
| 130 | #endif |
| 131 | |
| 132 | /* Set locale for everybody except 'init' */ |
| 133 | if (ENABLE_LOCALE_SUPPORT && getpid() != 1) |
| 134 | setlocale(LC_ALL, ""); |
| 135 | |
| 136 | /* Redundant for busybox, but needed for individual applets */ |
Denis Vlasenko | d419a9f | 2007-10-08 20:45:42 +0000 | [diff] [blame^] | 137 | if (argv[1] && strcmp(argv[1], "--help") == 0) |
Denis Vlasenko | ac7d0e3 | 2007-10-08 19:32:12 +0000 | [diff] [blame] | 138 | bb_show_usage(); |
| 139 | } |