New applet, fold

coreutils/Config.in

@@ -165,6 +165,12 @@ if !CONFIG_HUSH && !CONFIG_LASH && !CONFIG_MSH
 	      Please submit a patch to add help text for this item.
 endif
 
+config CONFIG_FOLD
+	bool "fold"
+	default n
+	help
+	 Wrap text to fit a specific width.
+
 config CONFIG_HEAD
 	bool "head"
 	default n

coreutils/Makefile.in

@@ -43,6 +43,7 @@ COREUTILS-$(CONFIG_ECHO)		+= echo.o
 COREUTILS-$(CONFIG_ENV)		+= env.o
 COREUTILS-$(CONFIG_EXPR)		+= expr.o
 COREUTILS-$(CONFIG_FALSE)		+= false.o
+COREUTILS-$(CONFIG_FOLD)	+= fold.o
 COREUTILS-$(CONFIG_HEAD)	+= head.o
 COREUTILS-$(CONFIG_HOSTID)		+= hostid.o
 COREUTILS-$(CONFIG_ID)			+= id.o

coreutils/fold.c

@@ -0,0 +1,202 @@
+/* fold -- wrap each input line to fit in specified width.
+
+   Written by David MacKenzie, djm@gnu.ai.mit.edu.
+   Copyright (C) 91, 1995-2002 Free Software Foundation, Inc.
+
+   Modified for busybox based on coreutils v 5.0
+   Copyright (C) 2003 Glenn McGrath <bug1@optushome.com.au>
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+*/
+
+#include <ctype.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <getopt.h>
+#include <sys/types.h>
+
+#include "busybox.h"
+
+/* If nonzero, count bytes, not column positions. */
+static int count_bytes;
+
+/* Assuming the current column is COLUMN, return the column that
+   printing C will move the cursor to.
+   The first column is 0. */
+
+static int adjust_column(int column, char c)
+{
+	if (!count_bytes) {
+		if (c == '\b') {
+			if (column > 0)
+				column--;
+		} else if (c == '\r')
+			column = 0;
+		else if (c == '\t')
+			column = column + 8 - column % 8;
+		else			/* if (isprint (c)) */
+			column++;
+	} else
+		column++;
+	return column;
+}
+
+extern int fold_main(int argc, char **argv)
+{
+	/* If nonzero, try to break on whitespace. */
+	int break_spaces;
+
+	/* If nonzero, at least one of the files we read was standard input. */
+	int have_read_stdin;
+
+	int width = 80;
+	int i;
+	int optc;
+	int errs = 0;
+
+	break_spaces = count_bytes = have_read_stdin = 0;
+
+	/* Turn any numeric options into -w options.  */
+	for (i = 1; i < argc; i++) {
+		char const *a = argv[i];
+
+		if (a[0] == '-') {
+			if (a[1] == '-' && !a[2])
+				break;
+			if (isdigit(a[1])) {
+				char *s = xmalloc(strlen(a) + 2);
+
+				s[0] = '-';
+				s[1] = 'w';
+				strcpy(s + 2, a + 1);
+				argv[i] = s;
+			}
+		}
+	}
+
+	while ((optc = getopt(argc, argv, "bsw:")) > 0) {
+		switch (optc) {
+			case 'b':		/* Count bytes rather than columns. */
+				count_bytes = 1;
+				break;
+			case 's':		/* Break at word boundaries. */
+				break_spaces = 1;
+				break;
+			case 'w': {	/* Line width. */
+				long int tmp_long;
+				char *end_ptr;
+
+				errno = 0;
+				tmp_long = strtol(optarg, &end_ptr, 10);
+				if (!end_ptr || errno || tmp_long < 1) {
+					bb_error_msg_and_die("invalid number of columns: `%s'", optarg);
+				}
+				width = (int) tmp_long;
+				break;
+			}
+			default:
+				bb_show_usage();
+		}
+	}
+
+	argv += optind;
+	if (!*argv) {
+		*--argv = "-";
+	}
+
+	do {
+		FILE *istream = bb_wfopen_input(*argv);
+		if (istream != NULL) {
+			int c;
+			int column = 0;		/* Screen column where next char will go. */
+			int offset_out = 0;	/* Index in `line_out' for next char. */
+			static char *line_out = NULL;
+			static int allocated_out = 0;
+
+			while ((c = getc(istream)) != EOF) {
+				if (offset_out + 1 >= allocated_out) {
+					allocated_out += 1024;
+					line_out = xrealloc(line_out, allocated_out);
+				}
+
+				if (c == '\n') {
+					line_out[offset_out++] = c;
+					fwrite(line_out, sizeof(char), (size_t) offset_out, stdout);
+					column = offset_out = 0;
+					continue;
+				}
+
+rescan:
+				column = adjust_column(column, c);
+
+				if (column > width) {
+					/* This character would make the line too long.
+			 		  Print the line plus a newline, and make this character
+					   start the next line. */
+					if (break_spaces) {
+						/* Look for the last blank. */
+						int logical_end;
+
+						for (logical_end = offset_out - 1; logical_end >= 0; logical_end--) {
+							if (isblank(line_out[logical_end])) {
+								break;
+							}
+						}
+						if (logical_end >= 0) {
+							/* Found a blank.  Don't output the part after it. */
+							logical_end++;
+							fwrite(line_out, sizeof(char), (size_t) logical_end, stdout);
+							putchar('\n');
+							/* Move the remainder to the beginning of the next line.
+							   The areas being copied here might overlap. */
+							memmove(line_out, line_out + logical_end, offset_out - logical_end);
+							offset_out -= logical_end;
+							for (column = i = 0; i < offset_out; i++) {
+								column = adjust_column(column, line_out[i]);
+							}
+							goto rescan;
+						}
+					} else {
+						if (offset_out == 0) {
+							line_out[offset_out++] = c;
+							continue;
+						}
+					}
+					line_out[offset_out++] = '\n';
+					fwrite(line_out, sizeof(char), (size_t) offset_out, stdout);
+					column = offset_out = 0;
+					goto rescan;
+				}
+
+				line_out[offset_out++] = c;
+			}
+
+			if (offset_out) {
+				fwrite(line_out, sizeof(char), (size_t) offset_out, stdout);
+			}
+
+			if (ferror(istream) || bb_fclose_nonstdin(istream)) {
+				bb_perror_msg("%s", *argv);	/* Avoid multibyte problems. */
+				errs |= EXIT_FAILURE;
+			}
+		} else {
+			errs |= EXIT_FAILURE;
+		}
+	} while (*++argv);
+
+	bb_fflush_stdout_and_exit(errs);
+}

include/applets.h

@@ -202,6 +202,9 @@
 #ifdef CONFIG_FIND
 	APPLET(find, find_main, _BB_DIR_USR_BIN, _BB_SUID_NEVER)
 #endif
+#ifdef CONFIG_FOLD
+	APPLET(fold, fold_main, _BB_DIR_USR_BIN, _BB_SUID_NEVER)
+#endif
 #ifdef CONFIG_FREE
 	APPLET(free, free_main, _BB_DIR_USR_BIN, _BB_SUID_NEVER)
 #endif

include/usage.h

@@ -627,6 +627,16 @@
 	"$ find / -name /etc/passwd\n" \
 	"/etc/passwd\n"
 
+#define fold_trivial_usage \
+	"[bsw] [FILE]"
+#define fold_full_usage \
+	"Wrap input lines in each FILE (standard input by default), writing to\n" \
+	"standard output.\n\n" \
+	"Options:\n" \
+	"\t-b\tcount bytes rather than columns\n" \
+	"\t-s\tbreak at spaces\n" \
+	"\t-w\tuse WIDTH columns instead of 80\n"
+
 #define free_trivial_usage \
 	""
 #define free_full_usage \