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authorGravatar Denis Vlasenko <vda.linux@googlemail.com>2007-10-08 19:32:12 +0000
committerGravatar Denis Vlasenko <vda.linux@googlemail.com>2007-10-08 19:32:12 +0000
commitac7d0e375e9ea6241b3ebca67b8cdb5128327535 (patch)
tree597583c807c38817606e6966522063a4de3f128d /libbb
parent642a52d65e239c43f38ed6e98994191f24290490 (diff)
downloadbusybox-ac7d0e375e9ea6241b3ebca67b8cdb5128327535.tar.gz
busybox-ac7d0e375e9ea6241b3ebca67b8cdb5128327535.tar.bz2
add libbb/appletlib.c
Diffstat (limited to 'libbb')
-rw-r--r--libbb/appletlib.c139
1 files changed, 139 insertions, 0 deletions
diff --git a/libbb/appletlib.c b/libbb/appletlib.c
new file mode 100644
index 000000000..626c25a8f
--- /dev/null
+++ b/libbb/appletlib.c
@@ -0,0 +1,139 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Support for main() which needs to end up in libbusybox, not busybox,
+ * if one builds libbusybox.
+ *
+ * Copyright (C) 2007 Denys Vlasenko <vda.linux@googlemail.com>
+ *
+ * Licensed under GPLv2, see file License in this tarball for details.
+ */
+
+#include <assert.h>
+#include "busybox.h"
+
+
+/* Declare <applet>_main() */
+#define PROTOTYPES
+#include "applets.h"
+#undef PROTOTYPES
+
+#if ENABLE_SHOW_USAGE && !ENABLE_FEATURE_COMPRESS_USAGE
+/* Define usage_messages[] */
+static const char usage_messages[] ALIGN1 = ""
+#define MAKE_USAGE
+#include "usage.h"
+#include "applets.h"
+;
+#undef MAKE_USAGE
+#else
+#define usage_messages 0
+#endif /* SHOW_USAGE */
+
+/* Define struct bb_applet applets[] */
+#include "applets.h"
+
+#if ENABLE_FEATURE_SH_STANDALONE
+/* -1 because last entry is NULL */
+const unsigned short NUM_APPLETS = ARRAY_SIZE(applets) - 1;
+#endif
+
+
+#if ENABLE_FEATURE_COMPRESS_USAGE
+
+#include "usage_compressed.h"
+#include "unarchive.h"
+
+static const char *unpack_usage_messages(void)
+{
+ char *outbuf = NULL;
+ bunzip_data *bd;
+ int i;
+
+ i = start_bunzip(&bd,
+ /* src_fd: */ -1,
+ /* inbuf: */ packed_usage,
+ /* len: */ sizeof(packed_usage));
+ /* read_bunzip can longjmp to start_bunzip, and ultimately
+ * end up here with i != 0 on read data errors! Not trivial */
+ if (!i) {
+ /* Cannot use xmalloc: will leak bd in NOFORK case! */
+ outbuf = malloc_or_warn(SIZEOF_usage_messages);
+ if (outbuf)
+ read_bunzip(bd, outbuf, SIZEOF_usage_messages);
+ }
+ dealloc_bunzip(bd);
+ return outbuf;
+}
+#define dealloc_usage_messages(s) free(s)
+
+#else
+
+#define unpack_usage_messages() usage_messages
+#define dealloc_usage_messages(s) ((void)(s))
+
+#endif /* FEATURE_COMPRESS_USAGE */
+
+
+void bb_show_usage(void)
+{
+ if (ENABLE_SHOW_USAGE) {
+ const char *format_string;
+ const char *p;
+ const char *usage_string = p = unpack_usage_messages();
+ const struct bb_applet *ap = find_applet_by_name(applet_name);
+ int i;
+
+ if (!ap) /* never happens, paranoia */
+ xfunc_die();
+
+ i = ap - applets;
+ while (i) {
+ while (*p++) continue;
+ i--;
+ }
+
+ fprintf(stderr, "%s multi-call binary\n", bb_banner);
+ format_string = "\nUsage: %s %s\n\n";
+ if (*p == '\b')
+ format_string = "\nNo help available.\n\n";
+ fprintf(stderr, format_string, applet_name, p);
+ dealloc_usage_messages((char*)usage_string);
+ }
+ xfunc_die();
+}
+
+
+static int applet_name_compare(const void *name, const void *vapplet)
+{
+ const struct bb_applet *applet = vapplet;
+
+ return strcmp(name, applet->name);
+}
+
+const struct bb_applet *find_applet_by_name(const char *name)
+{
+ /* Do a binary search to find the applet entry given the name. */
+ return bsearch(name, applets, ARRAY_SIZE(applets)-1, sizeof(applets[0]),
+ applet_name_compare);
+}
+
+
+#ifdef __GLIBC__
+/* Make it reside in R/W memory: */
+int *const bb_errno __attribute__ ((section (".data")));
+#endif
+
+void bbox_prepare_main(char **argv)
+{
+#ifdef __GLIBC__
+ (*(int **)&bb_errno) = __errno_location();
+#endif
+
+ /* Set locale for everybody except 'init' */
+ if (ENABLE_LOCALE_SUPPORT && getpid() != 1)
+ setlocale(LC_ALL, "");
+
+ /* Redundant for busybox, but needed for individual applets */
+ if (argv[1] && strcmp(argv[1], "--help") == 0)
+ bb_show_usage();
+}