summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorMarek Polacek <mmpolacek@gmail.com>2010-06-22 10:53:35 (GMT)
committer Denys Vlasenko <vda.linux@googlemail.com>2010-06-22 10:53:35 (GMT)
commitfc6f6e933c20e6016d19339ac472f6af3d05d4c3 (patch)
tree00a93283553b40b34ec39516e4bd45f93bafd40d
parent6d9c88ad982dbe9cb9d5c375f42a4eb8d4aef39f (diff)
downloadbusybox-fc6f6e933c20e6016d19339ac472f6af3d05d4c3.tar.gz
busybox-fc6f6e933c20e6016d19339ac472f6af3d05d4c3.tar.bz2
rev: new applet
text data bss dec hexfilename 377 0 0 377 179rev.o Signed-off-by: Marek Polacek <mmpolacek@gmail.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rw-r--r--util-linux/rev.c121
1 files changed, 121 insertions, 0 deletions
diff --git a/util-linux/rev.c b/util-linux/rev.c
new file mode 100644
index 0000000..fa3a453
--- /dev/null
+++ b/util-linux/rev.c
@@ -0,0 +1,121 @@
+/*
+ * rev implementation for busybox
+ *
+ * Copyright (C) 2010 Marek Polacek <mmpolacek@gmail.com>
+ *
+ * Licensed under GPLv2, see file License in this tarball for details.
+ */
+
+//applet:IF_REV(APPLET(rev, _BB_DIR_BIN, _BB_SUID_DROP))
+
+//kbuild:lib-$(CONFIG_REV) += rev.o
+
+//config:config REV
+//config: bool "rev"
+//config: default y
+//config: help
+//config: Reverse lines of a file or files.
+
+//usage:#define rev_trivial_usage
+//usage: "[FILE]..."
+//usage:#define rev_full_usage "\n\n"
+//usage: "Reverse lines of FILE"
+
+#include "libbb.h"
+#include "unicode.h"
+
+#undef CHAR_T
+#if ENABLE_UNICODE_SUPPORT
+# define CHAR_T wchar_t
+#else
+# define CHAR_T char
+#endif
+
+/* In-place invert */
+static void strrev(CHAR_T *s, int len)
+{
+ int i;
+
+ if (len != 0) {
+ len--;
+ if (len != 0 && s[len] == '\n')
+ len--;
+ }
+
+ for (i = 0; i < len; i++, len--) {
+ CHAR_T c = s[i];
+ s[i] = s[len];
+ s[len] = c;
+ }
+}
+
+int rev_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int rev_main(int argc UNUSED_PARAM, char **argv)
+{
+ int retval;
+ size_t bufsize;
+ char *buf;
+
+ init_unicode();
+
+ getopt32(argv, "");
+ argv += optind;
+ if (!argv[0])
+ argv = (char **)&bb_argv_dash;
+
+ retval = EXIT_SUCCESS;
+ bufsize = 256;
+ buf = xmalloc(bufsize);
+ do {
+ size_t pos;
+ FILE *fp;
+
+ fp = fopen_or_warn_stdin(*argv++);
+ if (!fp) {
+ retval = EXIT_FAILURE;
+ continue;
+ }
+
+ pos = 0;
+ while (1) {
+ /* Read one line */
+ buf[bufsize - 1] = 1; /* not 0 */
+ if (!fgets(buf + pos, bufsize - pos, fp))
+ break; /* EOF/error */
+ if (buf[bufsize - 1] == '\0' /* fgets filled entire buffer */
+ && buf[bufsize - 2] != '\n' /* and did not read '\n' */
+ && !feof(fp)
+ ) {
+ /* Line is too long, extend buffer */
+ pos = bufsize - 1;
+ bufsize += 64 + bufsize / 8;
+ buf = xrealloc(buf, bufsize);
+ continue;
+ }
+
+ /* Process and print it */
+#if ENABLE_UNICODE_SUPPORT
+ {
+ wchar_t *tmp = xmalloc(bufsize * sizeof(wchar_t));
+ /* Convert to wchar_t (might error out!) */
+ int len = mbstowcs(tmp, buf, bufsize);
+ if (len >= 0) {
+ strrev(tmp, len);
+ /* Convert back to char */
+ wcstombs(buf, tmp, bufsize);
+ }
+ free(tmp);
+ }
+#else
+ strrev(buf, strlen(buf));
+#endif
+ fputs(buf, stdout);
+ }
+ fclose(fp);
+ } while (*argv);
+
+ if (ENABLE_FEATURE_CLEAN_UP)
+ free(buf);
+
+ fflush_stdout_and_exit(retval);
+}