Another nice cleanup from Larry. This adds a new last_char_is() function and

uses it to avoid possible buffer underruns whn strlen is zero, and avoid the
possible space-hogging inline of strlen() in several cases.
 -Erik

Makefile

@@ -248,7 +248,7 @@ process_escape_sequence.c read_package_field.c read_text_file_to_buffer.c \
 recursive_action.c safe_read.c safe_strncpy.c seek_ared_file.c syscalls.c \
 syslog_msg_with_name.c time_string.c trim.c untar.c unzip.c vdprintf.c \
 verror_msg.c vperror_msg.c wfopen.c xfuncs.c xgetcwd.c xregcomp.c interface.c \
-remove_file.c
+remove_file.c last_char_is.c
 LIBBB_OBJS=$(patsubst %.c,$(LIBBB)/%.o, $(LIBBB_CSRC))
 LIBBB_CFLAGS = -I$(LIBBB)
 ifneq ($(strip $(BB_SRC_DIR)),)

archival/dpkg.c

@@ -583,7 +583,7 @@ static int status_merge(void *status, package_t *pkgs)
 	 */
 	if ((fin = fopen(statusfile, "r")) != NULL) {
 		while (((line = get_line_from_file(fin)) != NULL) && !feof(fin)) { 
-			line[strlen(line) - 1] = '\0'; /* trim newline */
+			chomp(line); /* trim newline */
 			/* If we see a package header, find out if it's a package
 			 * that we have processed. if so, we skip that block for
 			 * now (write it at the end).

archival/tar.c

@@ -706,7 +706,7 @@ static int readTarFile(int tarFd, int extractFlag, int listFlag,
 			case REGTYPE0:
 				/* If the name ends in a '/' then assume it is
 				 * supposed to be a directory, and fall through */
-				if (header.name[strlen(header.name)-1] != '/') {
+				if (last_char_is(header.name,'/')) {
 					if (tarExtractRegularFile(&header, extractFlag, tostdoutFlag)==FALSE)
 						errorFlag=TRUE;
 					break;

coreutils/cut.c

@@ -75,7 +75,7 @@ static void decompose_list(const char *list)
 	/* handle multi-value cases */
 	else if (nminus == 1) {
 		/* handle 'N-' case */
-		if (list[strlen(list) - 1] == '-') {
+		if (last_char_is(list,'-')) {
 			startpos = strtol(list, &ptr, 10);
 		}
 		/* handle '-M' case */

cut.c

@@ -75,7 +75,7 @@ static void decompose_list(const char *list)
 	/* handle multi-value cases */
 	else if (nminus == 1) {
 		/* handle 'N-' case */
-		if (list[strlen(list) - 1] == '-') {
+		if (last_char_is(list,'-')) {
 			startpos = strtol(list, &ptr, 10);
 		}
 		/* handle '-M' case */

dpkg.c

@@ -583,7 +583,7 @@ static int status_merge(void *status, package_t *pkgs)
 	 */
 	if ((fin = fopen(statusfile, "r")) != NULL) {
 		while (((line = get_line_from_file(fin)) != NULL) && !feof(fin)) { 
-			line[strlen(line) - 1] = '\0'; /* trim newline */
+			chomp(line); /* trim newline */
 			/* If we see a package header, find out if it's a package
 			 * that we have processed. if so, we skip that block for
 			 * now (write it at the end).

editors/vi.c

@@ -19,7 +19,7 @@
  */
 
 char *vi_Version =
-	"$Id: vi.c,v 1.4 2001/04/16 15:46:44 andersen Exp $";
+	"$Id: vi.c,v 1.5 2001/04/26 15:56:47 andersen Exp $";
 
 /*
  * To compile for standalone use:
@@ -1745,7 +1745,7 @@ static void colon(Byte * buf)
 	while (isblnk(*buf))
 		buf++;
 	strcpy((char *) args, (char *) buf);
-	if (cmd[strlen((char *) cmd) - 1] == '!') {
+	if (last_char_is((char *)cmd,'!')) {
 		useforce = TRUE;
 		cmd[strlen((char *) cmd) - 1] = '\0';	// get rid of !
 	}

include/libbb.h

@@ -218,6 +218,7 @@ int klogctl(int type, char * b, int len);
 
 char *xgetcwd(char *cwd);
 char *concat_path_file(const char *path, const char *filename);
+int last_char_is(const char *s, const int c);
 
 typedef struct ar_headers_s {
 	char *name;

libbb/last_char_is.c

@@ -0,0 +1,33 @@
+/*
+ * busybox library eXtended function
+ *
+ * Copyright (C) 2001 Larry Doolittle, <ldoolitt@recycle.lbl.gov>
+ *
+ * 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 of the License, 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 "libbb.h"
+
+/* Find out if the last character of a string matches the one given Don't
+ * underrun the buffer if the string length is 0.  Also avoids a possible
+ * space-hogging inline of strlen() per usage.
+ */
+int last_char_is(const char *s, const int c)
+{
+	int  l = strlen(s);
+	if (l==0) return 0;
+	return (s[l-1] == c);
+}

libbb/libbb.h

@@ -218,6 +218,7 @@ int klogctl(int type, char * b, int len);
 
 char *xgetcwd(char *cwd);
 char *concat_path_file(const char *path, const char *filename);
+int last_char_is(const char *s, const int c);
 
 typedef struct ar_headers_s {
 	char *name;

tar.c

@@ -706,7 +706,7 @@ static int readTarFile(int tarFd, int extractFlag, int listFlag,
 			case REGTYPE0:
 				/* If the name ends in a '/' then assume it is
 				 * supposed to be a directory, and fall through */
-				if (header.name[strlen(header.name)-1] != '/') {
+				if (last_char_is(header.name,'/')) {
 					if (tarExtractRegularFile(&header, extractFlag, tostdoutFlag)==FALSE)
 						errorFlag=TRUE;
 					break;

vi.c

@@ -19,7 +19,7 @@
  */
 
 char *vi_Version =
-	"$Id: vi.c,v 1.4 2001/04/16 15:46:44 andersen Exp $";
+	"$Id: vi.c,v 1.5 2001/04/26 15:56:47 andersen Exp $";
 
 /*
  * To compile for standalone use:
@@ -1745,7 +1745,7 @@ static void colon(Byte * buf)
 	while (isblnk(*buf))
 		buf++;
 	strcpy((char *) args, (char *) buf);
-	if (cmd[strlen((char *) cmd) - 1] == '!') {
+	if (last_char_is((char *)cmd,'!')) {
 		useforce = TRUE;
 		cmd[strlen((char *) cmd) - 1] = '\0';	// get rid of !
 	}