diff --git a/e2fsprogs/old_e2fsprogs/blkid/devname.c b/e2fsprogs/old_e2fsprogs/blkid/devname.c
index 348e5d42e..fad92cb31 100644
--- a/e2fsprogs/old_e2fsprogs/blkid/devname.c
+++ b/e2fsprogs/old_e2fsprogs/blkid/devname.c
@@ -258,7 +258,7 @@ int blkid_probe_all(blkid_cache cache)
 {
 	FILE *proc;
 	char line[1024];
-	char ptname0[128], ptname1[128], *ptname = 0;
+	char ptname0[128], ptname1[128], *ptname = NULL;
 	char *ptnames[2];
 	dev_t devs[2];
 	int ma, mi;
diff --git a/e2fsprogs/old_e2fsprogs/blkid/probe.c b/e2fsprogs/old_e2fsprogs/blkid/probe.c
index 1f7188e6d..77bfc737d 100644
--- a/e2fsprogs/old_e2fsprogs/blkid/probe.c
+++ b/e2fsprogs/old_e2fsprogs/blkid/probe.c
@@ -82,7 +82,7 @@ static void set_uuid(blkid_dev dev, uuid_t uuid)
 static void get_ext2_info(blkid_dev dev, unsigned char *buf)
 {
 	struct ext2_super_block *es = (struct ext2_super_block *) buf;
-	const char *label = 0;
+	const char *label = NULL;
 
 	DBG(DEBUG_PROBE, printf("ext2_sb.compat = %08X:%08X:%08X\n",
 		   blkid_le32(es->s_feature_compat),
@@ -168,7 +168,7 @@ static int probe_vfat(int fd __BLKID_ATTR((unused)),
 {
 	struct vfat_super_block *vs;
 	char serno[10];
-	const char *label = 0;
+	const char *label = NULL;
 	int label_len = 0;
 
 	vs = (struct vfat_super_block *)buf;
@@ -201,7 +201,7 @@ static int probe_msdos(int fd __BLKID_ATTR((unused)),
 {
 	struct msdos_super_block *ms = (struct msdos_super_block *) buf;
 	char serno[10];
-	const char *label = 0;
+	const char *label = NULL;
 	int label_len = 0;
 
 	if (strncmp(ms->ms_label, "NO NAME", 7)) {
@@ -232,7 +232,7 @@ static int probe_xfs(int fd __BLKID_ATTR((unused)),
 		     unsigned char *buf)
 {
 	struct xfs_super_block *xs;
-	const char *label = 0;
+	const char *label = NULL;
 
 	xs = (struct xfs_super_block *)buf;
 
@@ -250,7 +250,7 @@ static int probe_reiserfs(int fd __BLKID_ATTR((unused)),
 {
 	struct reiserfs_super_block *rs = (struct reiserfs_super_block *) buf;
 	unsigned int blocksize;
-	const char *label = 0;
+	const char *label = NULL;
 
 	blocksize = blkid_le16(rs->rs_blocksize);
 
@@ -277,7 +277,7 @@ static int probe_jfs(int fd __BLKID_ATTR((unused)),
 		     unsigned char *buf)
 {
 	struct jfs_super_block *js;
-	const char *label = 0;
+	const char *label = NULL;
 
 	js = (struct jfs_super_block *)buf;
 
@@ -295,7 +295,7 @@ static int probe_romfs(int fd __BLKID_ATTR((unused)),
 		       unsigned char *buf)
 {
 	struct romfs_super_block *ros;
-	const char *label = 0;
+	const char *label = NULL;
 
 	ros = (struct romfs_super_block *)buf;
 
@@ -312,7 +312,7 @@ static int probe_cramfs(int fd __BLKID_ATTR((unused)),
 		       unsigned char *buf)
 {
 	struct cramfs_super_block *csb;
-	const char *label = 0;
+	const char *label = NULL;
 
 	csb = (struct cramfs_super_block *)buf;
 
diff --git a/e2fsprogs/old_e2fsprogs/blkid/resolve.c b/e2fsprogs/old_e2fsprogs/blkid/resolve.c
index 0f92158e2..295ca61bf 100644
--- a/e2fsprogs/old_e2fsprogs/blkid/resolve.c
+++ b/e2fsprogs/old_e2fsprogs/blkid/resolve.c
@@ -65,7 +65,7 @@ char *blkid_get_devname(blkid_cache cache, const char *token,
 {
 	blkid_dev dev;
 	blkid_cache c = cache;
-	char *t = 0, *v = 0;
+	char *t = NULL, *v = NULL;
 	char *ret = NULL;
 
 	if (!token)
diff --git a/e2fsprogs/old_e2fsprogs/blkid/tag.c b/e2fsprogs/old_e2fsprogs/blkid/tag.c
index c0a93df98..8337b46b6 100644
--- a/e2fsprogs/old_e2fsprogs/blkid/tag.c
+++ b/e2fsprogs/old_e2fsprogs/blkid/tag.c
@@ -112,7 +112,7 @@ int blkid_set_tag(blkid_dev dev, const char *name,
 		  const char *value, const int vlength)
 {
 	blkid_tag	t = 0, head = 0;
-	char		*val = 0;
+	char		*val = NULL;
 
 	if (!dev || !name)
 		return -BLKID_ERR_PARAM;
diff --git a/e2fsprogs/old_e2fsprogs/e2fsck.c b/e2fsprogs/old_e2fsprogs/e2fsck.c
index 7e0996956..7384bc453 100644
--- a/e2fsprogs/old_e2fsprogs/e2fsck.c
+++ b/e2fsprogs/old_e2fsprogs/e2fsck.c
@@ -1539,7 +1539,7 @@ static errcode_t e2fsck_get_journal(e2fsck_t ctx, journal_t **ret_journal)
 	struct buffer_head      *bh;
 	struct inode            *j_inode = NULL;
 	struct kdev_s           *dev_fs = NULL, *dev_journal;
-	const char              *journal_name = 0;
+	const char              *journal_name = NULL;
 	journal_t               *journal = NULL;
 	errcode_t               retval = 0;
 	io_manager              io_ptr = 0;
@@ -6009,7 +6009,7 @@ static int check_dir_block(ext2_filsys fs,
 	struct dir_info         *subdir, *dir;
 	struct dx_dir_info      *dx_dir;
 #ifdef ENABLE_HTREE
-	struct dx_dirblock_info *dx_db = 0;
+	struct dx_dirblock_info *dx_db = NULL;
 #endif /* ENABLE_HTREE */
 	struct ext2_dir_entry   *dirent, *prev;
 	ext2_dirhash_t          hash;
@@ -7524,7 +7524,7 @@ static void e2fsck_pass4(e2fsck_t ctx)
 	struct ext2_inode       inode;
 	struct problem_context  pctx;
 	__u16   link_count, link_counted;
-	char    *buf = 0;
+	char    *buf = NULL;
 	int     group, maxgroup;
 
 	/* Pass 4 */
@@ -9670,7 +9670,7 @@ int fix_problem(e2fsck_t ctx, problem_t code, struct problem_context *pctx)
 {
 	ext2_filsys fs = ctx->fs;
 	const struct e2fsck_problem *ptr;
-	struct latch_descr *ldesc = 0;
+	struct latch_descr *ldesc = NULL;
 	const char *message;
 	int             def_yn, answer, ans;
 	int             print_answer = 0;
@@ -10669,7 +10669,7 @@ static errcode_t calculate_tree(ext2_filsys fs,
 				ext2_ino_t parent)
 {
 	struct ext2_dx_root_info        *root_info;
-	struct ext2_dx_entry            *root, *dx_ent = 0;
+	struct ext2_dx_entry            *root, *dx_ent = NULL;
 	struct ext2_dx_countlimit       *root_limit, *limit;
 	errcode_t                       retval;
 	char                            * block_start;
@@ -10821,7 +10821,7 @@ static errcode_t e2fsck_rehash_dir(e2fsck_t ctx, ext2_ino_t ino)
 	ext2_filsys             fs = ctx->fs;
 	errcode_t               retval;
 	struct ext2_inode       inode;
-	char                    *dir_buf = 0;
+	char                    *dir_buf = NULL;
 	struct fill_dir_struct  fd;
 	struct out_dir          outdir;
 
@@ -11559,7 +11559,7 @@ static void check_resize_inode(e2fsck_t ctx)
 	struct problem_context  pctx;
 	int             i, j, gdt_off, ind_off;
 	blk_t           blk, pblk, expect;
-	__u32           *dind_buf = 0, *ind_buf;
+	__u32           *dind_buf = NULL, *ind_buf;
 	errcode_t       retval;
 
 	clear_problem_context(&pctx);
@@ -12975,7 +12975,7 @@ static errcode_t PRS(int argc, char **argv, e2fsck_t *ret_ctx)
 	e2fsck_t        ctx;
 	errcode_t       retval;
 	struct sigaction        sa;
-	char            *extended_opts = 0;
+	char            *extended_opts = NULL;
 
 	retval = e2fsck_allocate_context(&ctx);
 	if (retval)
diff --git a/e2fsprogs/old_e2fsprogs/ext2fs/alloc.c b/e2fsprogs/old_e2fsprogs/ext2fs/alloc.c
index 590f23a7e..5021d72c9 100644
--- a/e2fsprogs/old_e2fsprogs/ext2fs/alloc.c
+++ b/e2fsprogs/old_e2fsprogs/ext2fs/alloc.c
@@ -109,7 +109,7 @@ errcode_t ext2fs_alloc_block(ext2_filsys fs, blk_t goal,
 {
 	errcode_t	retval;
 	blk_t		block;
-	char		*buf = 0;
+	char		*buf = NULL;
 
 	if (!block_buf) {
 		retval = ext2fs_get_mem(fs->blocksize, &buf);
diff --git a/e2fsprogs/old_e2fsprogs/ext2fs/bmap.c b/e2fsprogs/old_e2fsprogs/ext2fs/bmap.c
index b22fe3dbf..b2d0279d8 100644
--- a/e2fsprogs/old_e2fsprogs/ext2fs/bmap.c
+++ b/e2fsprogs/old_e2fsprogs/ext2fs/bmap.c
@@ -136,7 +136,7 @@ errcode_t ext2fs_bmap(ext2_filsys fs, ext2_ino_t ino, struct ext2_inode *inode,
 	struct ext2_inode inode_buf;
 	blk_t addr_per_block;
 	blk_t	b;
-	char	*buf = 0;
+	char	*buf = NULL;
 	errcode_t	retval = 0;
 	int		blocks_alloc = 0, inode_dirty = 0;
 
diff --git a/e2fsprogs/old_e2fsprogs/ext2fs/closefs.c b/e2fsprogs/old_e2fsprogs/ext2fs/closefs.c
index 008d5f36e..7ba7f22e2 100644
--- a/e2fsprogs/old_e2fsprogs/ext2fs/closefs.c
+++ b/e2fsprogs/old_e2fsprogs/ext2fs/closefs.c
@@ -206,8 +206,8 @@ errcode_t ext2fs_flush(ext2_filsys fs)
 	blk_t		group_block;
 	errcode_t	retval;
 	unsigned long	fs_state;
-	struct ext2_super_block *super_shadow = 0;
-	struct ext2_group_desc *group_shadow = 0;
+	struct ext2_super_block *super_shadow = NULL;
+	struct ext2_group_desc *group_shadow = NULL;
 	char	*group_ptr;
 	int	old_desc_blocks;
 #if BB_BIG_ENDIAN
diff --git a/e2fsprogs/old_e2fsprogs/ext2fs/dirblock.c b/e2fsprogs/old_e2fsprogs/ext2fs/dirblock.c
index 5d3f6a1bc..f651338e3 100644
--- a/e2fsprogs/old_e2fsprogs/ext2fs/dirblock.c
+++ b/e2fsprogs/old_e2fsprogs/ext2fs/dirblock.c
@@ -80,7 +80,7 @@ errcode_t ext2fs_write_dir_block2(ext2_filsys fs, blk_t block,
 	int		do_swap = 0;
 	errcode_t	retval;
 	char		*p, *end;
-	char		*buf = 0;
+	char		*buf = NULL;
 	struct ext2_dir_entry *dirent;
 
 	if ((fs->flags & EXT2_FLAG_SWAP_BYTES) ||
diff --git a/e2fsprogs/old_e2fsprogs/ext2fs/ext_attr.c b/e2fsprogs/old_e2fsprogs/ext2fs/ext_attr.c
index 7ee41f234..a2ba12d45 100644
--- a/e2fsprogs/old_e2fsprogs/ext2fs/ext_attr.c
+++ b/e2fsprogs/old_e2fsprogs/ext2fs/ext_attr.c
@@ -68,7 +68,7 @@ errcode_t ext2fs_adjust_ea_refcount(ext2_filsys fs, blk_t blk,
 {
 	errcode_t	retval;
 	struct ext2_ext_attr_header *header;
-	char	*buf = 0;
+	char	*buf = NULL;
 
 	if ((blk >= fs->super->s_blocks_count) ||
 	    (blk < fs->super->s_first_data_block))
diff --git a/e2fsprogs/old_e2fsprogs/ext2fs/finddev.c b/e2fsprogs/old_e2fsprogs/ext2fs/finddev.c
index 5e2cce940..e9e83fd7a 100644
--- a/e2fsprogs/old_e2fsprogs/ext2fs/finddev.c
+++ b/e2fsprogs/old_e2fsprogs/ext2fs/finddev.c
@@ -115,9 +115,9 @@ success:
  */
 char *ext2fs_find_block_device(dev_t device)
 {
-	struct dir_list *list = 0, *new_list = 0;
+	struct dir_list *list = NULL, *new_list = NULL;
 	struct dir_list *current;
-	char	*ret_path = 0;
+	char	*ret_path = NULL;
 
 	/*
 	 * Add the starting directories to search...
diff --git a/e2fsprogs/old_e2fsprogs/ext2fs/imager.c b/e2fsprogs/old_e2fsprogs/ext2fs/imager.c
index e82321efa..0f9cfcfaf 100644
--- a/e2fsprogs/old_e2fsprogs/ext2fs/imager.c
+++ b/e2fsprogs/old_e2fsprogs/ext2fs/imager.c
@@ -333,7 +333,7 @@ errout:
  */
 errcode_t ext2fs_image_bitmap_read(ext2_filsys fs, int fd, int flags)
 {
-	char		*ptr, *buf = 0;
+	char		*ptr, *buf = NULL;
 	int		size;
 	ssize_t		actual;
 	errcode_t	retval;
diff --git a/e2fsprogs/old_e2fsprogs/ext2fs/mkdir.c b/e2fsprogs/old_e2fsprogs/ext2fs/mkdir.c
index b63c5d7a6..93f47b06f 100644
--- a/e2fsprogs/old_e2fsprogs/ext2fs/mkdir.c
+++ b/e2fsprogs/old_e2fsprogs/ext2fs/mkdir.c
@@ -39,7 +39,7 @@ errcode_t ext2fs_mkdir(ext2_filsys fs, ext2_ino_t parent, ext2_ino_t inum,
 	ext2_ino_t		ino = inum;
 	ext2_ino_t		scratch_ino;
 	blk_t			blk;
-	char			*block = 0;
+	char			*block = NULL;
 
 	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
 
diff --git a/e2fsprogs/old_e2fsprogs/ext2fs/mkjournal.c b/e2fsprogs/old_e2fsprogs/ext2fs/mkjournal.c
index af47aee18..db1c8bff3 100644
--- a/e2fsprogs/old_e2fsprogs/ext2fs/mkjournal.c
+++ b/e2fsprogs/old_e2fsprogs/ext2fs/mkjournal.c
@@ -95,7 +95,7 @@ static errcode_t write_journal_file(ext2_filsys fs, char *filename,
 				    blk_t size, int flags)
 {
 	errcode_t	retval;
-	char		*buf = 0;
+	char		*buf = NULL;
 	int		fd, ret_size;
 	blk_t		i;
 
diff --git a/e2fsprogs/old_e2fsprogs/ext2fs/namei.c b/e2fsprogs/old_e2fsprogs/ext2fs/namei.c
index 4d4e3788c..14d48fb72 100644
--- a/e2fsprogs/old_e2fsprogs/ext2fs/namei.c
+++ b/e2fsprogs/old_e2fsprogs/ext2fs/namei.c
@@ -30,7 +30,7 @@ static errcode_t follow_link(ext2_filsys fs, ext2_ino_t root, ext2_ino_t dir,
 			     char *buf, ext2_ino_t *res_inode)
 {
 	char *pathname;
-	char *buffer = 0;
+	char *buffer = NULL;
 	errcode_t retval;
 	struct ext2_inode ei;
 
diff --git a/e2fsprogs/old_e2fsprogs/ext2fs/rw_bitmaps.c b/e2fsprogs/old_e2fsprogs/ext2fs/rw_bitmaps.c
index a5782db95..0ae0a8234 100644
--- a/e2fsprogs/old_e2fsprogs/ext2fs/rw_bitmaps.c
+++ b/e2fsprogs/old_e2fsprogs/ext2fs/rw_bitmaps.c
@@ -149,7 +149,7 @@ errcode_t ext2fs_write_block_bitmap (ext2_filsys fs)
 static errcode_t read_bitmaps(ext2_filsys fs, int do_inode, int do_block)
 {
 	dgrp_t i;
-	char *block_bitmap = 0, *inode_bitmap = 0;
+	char *block_bitmap = NULL, *inode_bitmap = NULL;
 	char *buf;
 	errcode_t retval;
 	int block_nbytes = (int) EXT2_BLOCKS_PER_GROUP(fs->super) / 8;
diff --git a/e2fsprogs/old_e2fsprogs/fsck.c b/e2fsprogs/old_e2fsprogs/fsck.c
index c0964f79d..dc029b65a 100644
--- a/e2fsprogs/old_e2fsprogs/fsck.c
+++ b/e2fsprogs/old_e2fsprogs/fsck.c
@@ -1166,7 +1166,7 @@ static void signal_cancel(int sig FSCK_ATTR((unused)))
 static void PRS(int argc, char **argv)
 {
 	int     i, j;
-	char    *arg, *dev, *tmp = 0;
+	char    *arg, *dev, *tmp = NULL;
 	char    options[128];
 	int     opt = 0;
 	int     opts_for_fsck = 0;
diff --git a/e2fsprogs/old_e2fsprogs/mke2fs.c b/e2fsprogs/old_e2fsprogs/mke2fs.c
index 32f0329c3..520364550 100644
--- a/e2fsprogs/old_e2fsprogs/mke2fs.c
+++ b/e2fsprogs/old_e2fsprogs/mke2fs.c
@@ -799,8 +799,8 @@ static int PRS(int argc, char **argv)
 	int		show_version_only = 0;
 	ext2_ino_t	num_inodes = 0;
 	errcode_t	retval;
-	char *		extended_opts = 0;
-	const char *	fs_type = 0;
+	char *		extended_opts = NULL;
+	const char *	fs_type = NULL;
 	blk_t		dev_size;
 	long		sysval;
 
diff --git a/shell/ash.c b/shell/ash.c
index 03904bbf8..8ffe67cca 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -2482,7 +2482,7 @@ static void hashcd(void);
 static int
 docd(const char *dest, int flags)
 {
-	const char *dir = 0;
+	const char *dir = NULL;
 	int err;
 
 	TRACE(("docd(\"%s\", %d) called\n", dest, flags));