expand, unexpand: new applets from Tito <farmatito@tiscali.it>

4 files changed, 237 insertions, 2 deletions

diff --git a/coreutils/Config.in b/coreutils/Config.in
index cb5241ef6..3370b2a5d 100644
--- a/coreutils/Config.in
+++ b/coreutils/Config.in
@@ -200,6 +200,19 @@ config FEATURE_ENV_LONG_OPTIONS
 	help
 	  Support long options for the env applet.
 
+config EXPAND
+	bool "expand"
+	default n
+	help
+	  By default, convert all tabs to spaces.
+
+config FEATURE_EXPAND_LONG_OPTIONS
+	bool "Enable long options"
+	default n
+	depends on EXPAND && GETOPT_LONG
+	help
+	  Support long options for the expand applet.
+
 config EXPR
 	bool "expr"
 	default n
@@ -655,6 +668,19 @@ config UNAME
 	help
 	  uname is used to print system information.
 
+config UNEXPAND
+	bool "unexpand"
+	default n
+	help
+	  By default, convert only leading sequences of blanks to tabs.
+
+config FEATURE_UNEXPAND_LONG_OPTIONS
+	bool "Enable long options"
+	default n
+	depends on UNEXPAND && GETOPT_LONG
+	help
+	  Support long options for the unexpand applet.
+
 config UNIQ
 	bool "uniq"
 	default n
diff --git a/coreutils/Kbuild b/coreutils/Kbuild
index fd67d6c85..ce21b3a89 100644
--- a/coreutils/Kbuild
+++ b/coreutils/Kbuild
@@ -31,6 +31,7 @@ lib-$(CONFIG_ECHO)      += echo.o
 lib-$(CONFIG_ASH)       += echo.o # used by ash
 lib-$(CONFIG_ENV)       += env.o
 lib-$(CONFIG_EXPR)      += expr.o
+lib-$(CONFIG_EXPAND)    += expand.o
 lib-$(CONFIG_FALSE)     += false.o
 lib-$(CONFIG_FOLD)      += fold.o
 lib-$(CONFIG_HEAD)      += head.o
@@ -74,6 +75,7 @@ lib-$(CONFIG_TR)        += tr.o
 lib-$(CONFIG_TRUE)      += true.o
 lib-$(CONFIG_TTY)       += tty.o
 lib-$(CONFIG_UNAME)     += uname.o
+lib-$(CONFIG_UNEXPAND)  += expand.o
 lib-$(CONFIG_UNIQ)      += uniq.o
 lib-$(CONFIG_USLEEP)    += usleep.o
 lib-$(CONFIG_UUDECODE)  += uudecode.o
diff --git a/coreutils/expand.c b/coreutils/expand.c
new file mode 100644
index 000000000..30815ff63
--- /dev/null
+++ b/coreutils/expand.c
@@ -0,0 +1,209 @@
+/* expand - convert tabs to spaces
+ * unexpand - convert spaces to tabs
+ *
+ * Copyright (C) 89, 91, 1995-2006 Free Software Foundation, Inc.
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ *
+ * David MacKenzie <djm@gnu.ai.mit.edu>
+ *
+ * Options for expand:
+ * -t num  --tabs=NUM      Convert tabs to num spaces (default 8 spaces).
+ * -i      --initial       Only convert initial tabs on each line to spaces.
+ *
+ * Options for unexpand:
+ * -a      --all           Convert all blanks, instead of just initial blanks.
+ * -f      --first-only    Convert only leading sequences of blanks (default).
+ * -t num  --tabs=NUM      Have tabs num characters apart instead of 8.
+ *
+ *  Busybox version (C) 2007 by Tito Ragusa <farmatito@tiscali.it>
+ *
+ *  Caveat: this versions of expand and unexpand don't accept tab lists.
+ */
+
+#include "libbb.h"
+
+enum {
+	OPT_INITIAL     = 1 << 0,
+	OPT_TABS        = 1 << 1,
+	OPT_ALL         = 1 << 2,
+};
+
+static void xputchar(char c)
+{
+	if (putchar(c) < 0)
+		bb_error_msg_and_die(bb_msg_write_error);
+}
+
+#if ENABLE_EXPAND
+static void expand(FILE *file, unsigned tab_size, unsigned opt)
+{
+	char *line;
+	char *ptr;
+	int convert;
+	int pos;
+
+	/* Increment tab_size by 1 locally.*/
+	tab_size++;
+
+	while ((line = xmalloc_fgets(file)) != NULL) {
+		convert = 1;
+		pos = 0;
+		ptr = line;
+		while (*line) {
+			pos++;
+			if (*line == '\t' && convert) {
+				for (; pos < tab_size; pos++) {
+					xputchar(' ');
+				}
+			} else {
+				if ((opt & OPT_INITIAL) && !isblank(*line)) {
+					convert = 0;
+				}
+				xputchar(*line);
+			}
+			if (pos == tab_size) {
+				pos = 0;
+			}
+			line++;
+		}
+		free(ptr);
+	}
+}
+#endif
+
+#if ENABLE_UNEXPAND
+static void unexpand(FILE *file, unsigned int tab_size, unsigned opt)
+{
+	char *line;
+	char *ptr;
+	int convert;
+	int pos;
+	int i = 0;
+	int column = 0;
+
+	while ((line = xmalloc_fgets(file)) != NULL) {
+		convert = 1;
+		pos = 0;
+		ptr = line;
+		while (*line) {
+			while ((*line == ' ' || *line == '\t') && convert) {
+				pos += (*line == ' ') ? 1 : tab_size;
+				line++;
+				column++;
+				if ((opt & OPT_ALL) && column == tab_size) {
+					column = 0;
+					goto put_tab;
+				}
+			}
+			if (pos) {
+				i = pos / tab_size;
+				if (i) {
+					for (; i > 0; i--) {
+ put_tab:
+						xputchar('\t');
+					}
+				} else {
+					for (i = pos % tab_size; i > 0; i--) {
+						xputchar(' ');
+					}
+				}
+				pos = 0;
+			} else {
+				if (opt & OPT_INITIAL) {
+					convert = 0;
+				}
+				if (opt & OPT_ALL) {
+					column++;
+				}
+				xputchar(*line);
+				line++;
+			}
+		}
+		free(ptr);
+	}
+}
+#endif
+
+int expand_main(int argc, char **argv);
+int expand_main(int argc, char **argv)
+{
+	/* Default 8 spaces for 1 tab */
+	const char *opt_t = "8";
+	FILE *file;
+	unsigned tab_size;
+	unsigned opt;
+	int exit_status = EXIT_SUCCESS;
+
+#if ENABLE_FEATURE_EXPAND_LONG_OPTIONS
+	static const char expand_longopts[] ALIGN1 =
+		/* name, has_arg, val */
+		"initial\0"          No_argument       "i"
+		"tabs\0"             Required_argument "t"
+	;
+#endif
+#if ENABLE_FEATURE_UNEXPAND_LONG_OPTIONS
+	static const char unexpand_longopts[] ALIGN1 =
+		/* name, has_arg, val */
+		"first-only\0"       No_argument       "i"
+		"tabs\0"             Required_argument "t"
+		"all\0"              No_argument       "a"
+	;
+#endif
+
+	if (ENABLE_EXPAND && (!ENABLE_UNEXPAND || applet_name[0] == 'e')) {
+		USE_FEATURE_EXPAND_LONG_OPTIONS(applet_long_options = expand_longopts);
+		opt = getopt32(argc, argv, "it:", &opt_t);
+	} else if (ENABLE_UNEXPAND) {
+		USE_FEATURE_UNEXPAND_LONG_OPTIONS(applet_long_options = unexpand_longopts);
+		/* -t NUM sets also -a */
+		opt_complementary = "ta";
+		opt = getopt32(argc, argv, "ft:a", &opt_t);
+		/* -f --first-only is the default */
+		if (!(opt & OPT_ALL)) opt |= OPT_INITIAL;
+	}
+	tab_size = xatou_range(opt_t, 1, UINT_MAX);
+
+	argv += optind;
+
+	/* If no args are given, read from stdin */
+	if (!*argv) {
+		*--argv = (char*)bb_msg_standard_input;
+		goto use_stdin;
+	}
+
+	do {
+		if (NOT_LONE_CHAR(*argv, '-')) {
+			file = fopen_or_warn(*argv, "r");
+			if (!file) {
+				exit_status = EXIT_FAILURE;
+				continue;
+			}
+		} else {
+ use_stdin:
+			file = stdin;
+		}
+
+		if (ENABLE_EXPAND && (!ENABLE_UNEXPAND || applet_name[0] == 'e'))
+			USE_EXPAND(expand(file, tab_size, opt));
+		else if (ENABLE_UNEXPAND)
+			USE_UNEXPAND(unexpand(file, tab_size, opt));
+
+		/* Check and close the file */
+		/* We do want all of them to execute, thus | instead of || */
+		if (ferror(file) | fclose_if_not_stdin(file)) {
+			bb_perror_msg("%s", *argv);
+			exit_status = EXIT_FAILURE;
+		}
+		/* If stdin also clear EOF */
+		if (file == stdin) 
+			clearerr(file);
+	} while (*++argv);
+
+	/* Now close stdin also */
+	/* (if we didn't read from it, it's a no-op) */
+	if (fclose(stdin))
+		bb_perror_msg_and_die(bb_msg_standard_input);
+
+	fflush_stdout_and_exit(exit_status);
+}
diff --git a/coreutils/expr.c b/coreutils/expr.c
index 318fee721..c2d966966 100644
--- a/coreutils/expr.c
+++ b/coreutils/expr.c
@@ -505,5 +505,3 @@ int expr_main(int argc, char **argv)
 
 	fflush_stdout_and_exit(null(v));
 }
-
-