Prefer streq/memeq when they will do

Gnulib’s new streq and memeq functions make code a bit more
readable and, we hope, a bit more reliable and easy to maintain.
* gnulib.modules: Add stringeq.
* lib/wordsplit.c (wordsplit_find_env):
* src/buffer.c (check_compressed_archive, check_tty)
(_open_archive, new_volume, try_new_volume)
(drop_volume_label_suffix):
* src/checkpoint.c (checkpoint_compile_action):
* src/compare.c (process_rawdata, diff_symlink):
* src/create.c (cachedir_file_p):
* src/delete.c (delete_archive_members):
* src/exclist.c (hg_addfn, get_vcs_ignore_file):
* src/extract.c (ds_compare, remove_delayed_set_stat)
(fixup_delayed_set_stat, apply_nonancestor_delayed_set_stat)
(extract_link):
* src/incremen.c (nfs_file_stat, compare_directory_canonical_names)
(procdir):
* src/list.c (read_header, decode_header):
* src/misc.c (replace_prefix):
* src/names.c (uname_to_uid, gname_to_gid, read_next_name)
(name_compare):
* src/sparse.c (check_data_region):
* src/suffix.c (find_compression_suffix):
* src/system.c (sys_detect_dev_null_output)
(sys_child_open_for_compress, sys_child_open_for_uncompress):
* src/tar.c (set_archive_format, tar_set_quoting_style)
(optloc_eq, set_use_compress_program_option, decode_signal)
(report_textual_dates, decode_options):
* src/update.c (update_archive):
* src/warning.c (set_warning_option):
* src/xattrs.c (xattrs_xattrs_set):
* src/xheader.c (xheader_keyword_override_p)
(xheader_set_keyword_equal, locate_handler)
(xheader_protected_keyword_p):
Prefer memeq/streq to memcmp/strcmp when either will do.

gnulib.modules

@@ -107,6 +107,7 @@ stpcpy
 stdopen
 strdup-posix
 strerror
+stringeq
 strnlen
 symlinkat
 sys_stat-h

lib/wordsplit.c

@@ -1020,7 +1020,7 @@ wordsplit_find_env (struct wordsplit *wsp, char const *name, idx_t len,
       for (i = 0; wsp->ws_env[i]; i++)
 	{
 	  idx_t elen = strlen (wsp->ws_env[i]);
-	  if (elen == len && memcmp (wsp->ws_env[i], name, elen) == 0)
+	  if (elen == len && memeq (wsp->ws_env[i], name, elen))
 	    {
 	      *ret = wsp->ws_env[i + 1];
 	      return WRDSE_OK;

src/buffer.c

@@ -419,17 +419,16 @@ check_compressed_archive (bool *pshort)
   read_full_records = sfr;
 
   if (record_start != record_end /* no files smaller than BLOCKSIZE */
-      && (memcmp (record_start->header.magic, TMAGIC, sizeof TMAGIC) == 0
-          || (memcmp (record_start->buffer + offsetof (struct posix_header,
-						       magic),
-		      OLDGNU_MAGIC, sizeof OLDGNU_MAGIC)
-	      == 0))
+      && (memeq (record_start->header.magic, TMAGIC, sizeof TMAGIC)
+          || memeq (record_start->buffer + offsetof (struct posix_header,
+						     magic),
+		    OLDGNU_MAGIC, sizeof OLDGNU_MAGIC))
       && tar_checksum (record_start, true) == HEADER_SUCCESS)
     /* Probably a valid header */
     return ct_tar;
 
   for (p = magic + 2; p < magic + n_zip_magic; p++)
-    if (memcmp (record_start->buffer, p->magic, p->length) == 0)
+    if (memeq (record_start->buffer, p->magic, p->length))
       return p->type;
 
   return ct_none;
@@ -679,7 +678,7 @@ static void
 check_tty (enum access_mode mode)
 {
   /* Refuse to read archive from and write it to a tty. */
-  if (strcmp (archive_name_array[0], "-") == 0
+  if (streq (archive_name_array[0], "-")
       && isatty (mode == ACCESS_READ ? STDIN_FILENO : STDOUT_FILENO))
     {
       paxfatal (0, (mode == ACCESS_READ
@@ -777,10 +776,10 @@ _open_archive (enum access_mode wanted_access)
 
       if (!index_file_name
           && wanted_access == ACCESS_WRITE
-          && strcmp (archive_name_array[0], "-") == 0)
+          && streq (archive_name_array[0], "-"))
         stdlis = stderr;
     }
-  else if (strcmp (archive_name_array[0], "-") == 0)
+  else if (streq (archive_name_array[0], "-"))
     {
       read_full_records = true; /* could be a pipe, be safe */
       if (verify_option)
@@ -1366,7 +1365,7 @@ new_volume (enum access_mode mode)
         change_tape_menu (read_file);
     }
 
-  if (strcmp (archive_name_cursor[0], "-") == 0)
+  if (streq (archive_name_cursor[0], "-"))
     {
       read_full_records = true;
       archive = STDIN_FILENO;
@@ -1540,7 +1539,7 @@ try_new_volume (void)
 	  return false;
 	}
 
-      if (strcmp (continued_file_name, bufmap_head->file_name) != 0)
+      if (!streq (continued_file_name, bufmap_head->file_name))
         {
           if ((archive_format == GNU_FORMAT || archive_format == OLDGNU_FORMAT)
               && strlen (bufmap_head->file_name) >= NAME_FIELD_SIZE
@@ -1598,7 +1597,7 @@ drop_volume_label_suffix (const char *label)
       prefix_len = i + 1;
 
   ptrdiff_t len = prefix_len - VOLUME_TEXT_LEN;
-  return (0 <= len && memcmp (label + len, VOLUME_TEXT, VOLUME_TEXT_LEN) == 0
+  return (0 <= len && memeq (label + len, VOLUME_TEXT, VOLUME_TEXT_LEN)
 	  ? ximemdup0 (label, len)
 	  : NULL);
 }

src/checkpoint.c

@@ -97,11 +97,11 @@ checkpoint_compile_action (const char *str)
       checkpoint_state = CHKP_COMPILE;
     }
 
-  if (strcmp (str, ".") == 0 || strcmp (str, "dot") == 0)
+  if (streq (str, ".") || streq (str, "dot"))
     alloc_action (cop_dot, NULL);
-  else if (strcmp (str, "bell") == 0)
+  else if (streq (str, "bell"))
     alloc_action (cop_bell, NULL);
-  else if (strcmp (str, "echo") == 0)
+  else if (streq (str, "echo"))
     alloc_action (cop_echo, NULL)->v.command = NULL;
   else if (strncmp (str, "echo=", 5) == 0)
     alloc_action (cop_echo, str + 5);
@@ -118,7 +118,7 @@ checkpoint_compile_action (const char *str)
       if ((p == arg) | *p)
 	paxfatal (0, _("%s: not a valid timeout"), str);
     }
-  else if (strcmp (str, "totals") == 0)
+  else if (streq (str, "totals"))
     alloc_action (cop_totals, NULL);
   else if (strncmp (str, "wait=", 5) == 0)
     {

src/compare.c

@@ -106,7 +106,7 @@ process_rawdata (idx_t bytes, char *buffer)
       return false;
     }
 
-  if (memcmp (buffer, diff_buffer, bytes) != 0)
+  if (!memeq (buffer, diff_buffer, bytes))
     {
       report_difference (&current_stat_info, _("Contents differ"));
       return false;
@@ -278,7 +278,7 @@ diff_symlink (void)
       report_difference (&current_stat_info, NULL);
     }
   else if (status != len
-	   || memcmp (current_stat_info.link_name, linkbuf, len) != 0)
+	   || !memeq (current_stat_info.link_name, linkbuf, len))
     report_difference (&current_stat_info, _("Symlink differs"));
 
   if (linkbuf != buf)

src/create.c

@@ -115,7 +115,7 @@ cachedir_file_p (int fd)
     = "Signature: 8a477f597d28d172789f06886806bc55";
   char tagbuf[sizeof sig];
   return (read (fd, tagbuf, sizeof sig) == sizeof sig
-	  && memcmp (tagbuf, sig, sizeof sig) == 0);
+	  && memeq (tagbuf, sig, sizeof sig));
 }
 
 

src/delete.c

@@ -157,7 +157,7 @@ delete_archive_members (void)
 
   name_gather ();
   open_archive (ACCESS_UPDATE);
-  acting_as_filter = strcmp (archive_name_array[0], "-") == 0;
+  acting_as_filter = streq (archive_name_array[0], "-");
 
   /* Skip to the first member that matches the name list. */
   do

src/exclist.c

@@ -263,10 +263,10 @@ hg_addfn (struct exclude *ex, char const *pattern, int options, void *data)
     {
       for (pattern += 7; c_isspace (*pattern); ++pattern)
 	;
-      if (strcmp (pattern, "regexp") == 0)
+      if (streq (pattern, "regexp"))
 	/* FIXME: Regexps must be perl-style */
 	*hgopt = EXCLUDE_REGEX;
-      else if (strcmp (pattern, "glob") == 0)
+      else if (streq (pattern, "glob"))
 	*hgopt = EXCLUDE_WILDCARDS;
       /* Ignore unknown syntax */
       return;
@@ -306,7 +306,7 @@ get_vcs_ignore_file (const char *name)
   struct vcs_ignore_file *p;
 
   for (p = vcs_ignore_files; p->filename; p++)
-    if (strcmp (p->filename, name) == 0)
+    if (streq (p->filename, name))
       break;
 
   return p;

src/extract.c

@@ -230,7 +230,7 @@ static bool
 ds_compare (void const *a, void const *b)
 {
   struct delayed_set_stat const *dsa = a, *dsb = b;
-  return strcmp (dsa->file_name, dsb->file_name) == 0;
+  return streq (dsa->file_name, dsb->file_name);
 }
 
 /*  Set up to extract files.  */
@@ -704,7 +704,7 @@ remove_delayed_set_stat (const char *fname)
     {
       next = data->next;
       if (chdir_current == data->change_dir
-	  && strcmp (data->file_name, fname) == 0)
+	  && streq (data->file_name, fname))
 	{
 	  hash_remove (delayed_set_stat_table, data);
 	  free_delayed_set_stat (data);
@@ -726,7 +726,7 @@ fixup_delayed_set_stat (char const *src, char const *dst)
   for (data = delayed_set_stat_head; data; data = data->next)
     {
       if (chdir_current == data->change_dir
-	  && strcmp (data->file_name, src) == 0)
+	  && streq (data->file_name, src))
 	{
 	  free (data->file_name);
 	  data->file_name = xstrdup (dst);
@@ -1009,7 +1009,7 @@ apply_nonancestor_delayed_set_stat (char const *file_name, bool after_links)
 	      && file_name[data->file_name_len]
 	      && (ISSLASH (file_name[data->file_name_len])
 		  || ISSLASH (file_name[data->file_name_len - 1]))
-	      && memcmp (file_name, data->file_name, data->file_name_len) == 0))
+	      && memeq (file_name, data->file_name, data->file_name_len)))
 	break;
 
       chdir_do (data->change_dir);
@@ -1567,7 +1567,7 @@ extract_link (char *file_name, MAYBE_UNUSED char typeflag)
 
 	  return true;
 	}
-      else if ((e == EEXIST && strcmp (link_name, file_name) == 0)
+      else if ((e == EEXIST && streq (link_name, file_name))
 	       || ((fstatat (chdir_fd, link_name, &st1, AT_SYMLINK_NOFOLLOW)
 		    == 0)
 		   && (fstatat (chdir_fd, file_name, &st2, AT_SYMLINK_NOFOLLOW)

src/incremen.c

@@ -257,7 +257,7 @@ static bool
 nfs_file_stat (struct stat const *st)
 {
 #if HAVE_ST_FSTYPE_STRING
-  return strcmp (st->st_fstype, "nfs") == 0;
+  return streq (st->st_fstype, "nfs");
 #else
   return (st->st_dev >> (TYPE_WIDTH (st->st_dev) - 1)) & 1;
 #endif
@@ -277,7 +277,7 @@ compare_directory_canonical_names (void const *entry1, void const *entry2)
 {
   struct directory const *directory1 = entry1;
   struct directory const *directory2 = entry2;
-  return strcmp (directory1->caname, directory2->caname) == 0;
+  return streq (directory1->caname, directory2->caname);
 }
 
 static size_t
@@ -515,7 +515,7 @@ procdir (const char *name_buffer, struct tar_stat_info *st,
 	    }
 	}
 
-      if (strcmp (directory->name, name_buffer))
+      if (!streq (directory->name, name_buffer))
 	{
 	  *entry = 'N';
 	  return directory;
@@ -537,7 +537,7 @@ procdir (const char *name_buffer, struct tar_stat_info *st,
 						     stat_data->st_ino);
 	  if (d)
 	    {
-	      if (strcmp (d->name, name_buffer))
+	      if (!streq (d->name, name_buffer))
 		{
 		  warnopt (WARN_RENAME_DIRECTORY, 0,
 			   _("%s: Directory has been renamed from %s"),
@@ -580,7 +580,7 @@ procdir (const char *name_buffer, struct tar_stat_info *st,
 
       if (d)
 	{
-	  if (strcmp (d->name, name_buffer))
+	  if (!streq (d->name, name_buffer))
 	    {
 	      warnopt (WARN_RENAME_DIRECTORY, 0,
 		       _("%s: Directory has been renamed from %s"),

src/list.c

@@ -542,7 +542,7 @@ read_header (union block **return_block, struct tar_stat_info *info,
                  section 10.1.1.  */
 	      char *np = namebuf;
 
-	      if (h->prefix[0] && memcmp (h->magic, TMAGIC, sizeof TMAGIC) == 0)
+	      if (h->prefix[0] && memeq (h->magic, TMAGIC, sizeof TMAGIC))
 		{
 		  memcpy (np, h->prefix, sizeof h->prefix);
 		  np[sizeof h->prefix] = '\0';
@@ -613,7 +613,7 @@ decode_header (union block *header, struct tar_stat_info *stat_info,
   bool hbits;
   mode_t mode = MODE_FROM_HEADER (header->header.mode, &hbits);
 
-  if (memcmp (header->header.magic, TMAGIC, sizeof TMAGIC) == 0)
+  if (memeq (header->header.magic, TMAGIC, sizeof TMAGIC))
     {
       if (header->star_header.prefix[130] == 0
 	  && is_octal_digit (header->star_header.atime[0])
@@ -626,9 +626,8 @@ decode_header (union block *header, struct tar_stat_info *stat_info,
       else
 	format = USTAR_FORMAT;
     }
-  else if (memcmp (header->buffer + offsetof (struct posix_header, magic),
-		   OLDGNU_MAGIC, sizeof OLDGNU_MAGIC)
-	   == 0)
+  else if (memeq (header->buffer + offsetof (struct posix_header, magic),
+		  OLDGNU_MAGIC, sizeof OLDGNU_MAGIC))
     format = hbits ? OLDGNU_FORMAT : GNU_FORMAT;
   else
     format = V7_FORMAT;

src/misc.c

@@ -377,7 +377,7 @@ replace_prefix (char **pname, const char *samp, idx_t slen,
 {
   char *name = *pname;
   idx_t nlen = strlen (name);
-  if (nlen > slen && memcmp (name, samp, slen) == 0 && ISSLASH (name[slen]))
+  if (slen < nlen && memeq (name, samp, slen) && ISSLASH (name[slen]))
     {
       if (rlen > slen)
 	{

src/names.c

@@ -541,12 +541,12 @@ uname_to_uid (char const *uname, uid_t *uidp)
   struct passwd *passwd;
 
   if (cached_no_such_uname
-      && strcmp (uname, cached_no_such_uname) == 0)
+      && streq (uname, cached_no_such_uname))
     return false;
 
-  if (!cached_uname
-      || uname[0] != cached_uname[0]
-      || strcmp (uname, cached_uname) != 0)
+  if (! (cached_uname
+	 && uname[0] == cached_uname[0]
+	 && streq (uname, cached_uname)))
     {
       passwd = getpwnam (uname);
       if (passwd)
@@ -572,12 +572,12 @@ gname_to_gid (char const *gname, gid_t *gidp)
   struct group *group;
 
   if (cached_no_such_gname
-      && strcmp (gname, cached_no_such_gname) == 0)
+      && streq (gname, cached_no_such_gname))
     return false;
 
-  if (!cached_gname
-      || gname[0] != cached_gname[0]
-      || strcmp (gname, cached_gname) != 0)
+  if (! (cached_gname
+	 && gname[0] == cached_gname[0]
+	 && streq (gname, cached_gname)))
     {
       group = getgrnam (gname);
       if (group)
@@ -1016,7 +1016,7 @@ read_next_name (struct name_elt *ent, struct name_elt *ret)
 {
   if (!ent->v.file.fp)
     {
-      if (strcmp (ent->v.file.name, "-") == 0)
+      if (streq (ent->v.file.name, "-"))
 	{
 	  request_stdin ("-T");
 	  ent->v.file.fp = stdin;
@@ -1067,7 +1067,7 @@ read_next_name (struct name_elt *ent, struct name_elt *ret)
 	  return true;
 
 	case file_list_end:
-	  if (strcmp (ent->v.file.name, "-"))
+	  if (!streq (ent->v.file.name, "-"))
 	    fclose (ent->v.file.fp);
 	  ent->v.file.fp = NULL;
 	  name_list_advance ();
@@ -1707,7 +1707,7 @@ name_compare (void const *entry1, void const *entry2)
 {
   struct name const *name1 = entry1;
   struct name const *name2 = entry2;
-  return strcmp (name1->caname, name2->caname) == 0;
+  return streq (name1->caname, name2->caname);
 }
 
 

src/sparse.c

@@ -659,7 +659,7 @@ check_data_region (struct tar_sparse_file *file, idx_t i)
       idx_t bytes_read = full_read (file->fd, diff_buffer, rdsize);
       size_left -= bytes_read;
       mv_size_left (file->stat_info->archive_file_size - file->dumped_size);
-      if (memcmp (blk->buffer, diff_buffer, bytes_read) != 0)
+      if (!memeq (blk->buffer, diff_buffer, bytes_read))
 	{
 	  report_difference (file->stat_info, _("Contents differ"));
 	  return false;

src/suffix.c

@@ -75,7 +75,7 @@ find_compression_suffix (char const *name, idx_t *ret_len)
 	   p < (compression_suffixes
 		+ sizeof compression_suffixes / sizeof *compression_suffixes);
 	   p++)
-	if (strcmp (p->suffix, suf) == 0)
+	if (streq (p->suffix, suf))
 	  return p;
     }
   else if (ret_len)

src/system.c

@@ -95,7 +95,7 @@ sys_detect_dev_null_output (void)
 {
   static char const dev_null[] = "nul";
 
-  dev_null_output = (strcmp (archive_name_array[0], dev_null) == 0
+  dev_null_output = (streq (archive_name_array[0], dev_null)
 		     || (! _isrmt (archive)));
 }
 
@@ -200,7 +200,7 @@ sys_detect_dev_null_output (void)
 {
   static struct stat dev_null_stat;
 
-  dev_null_output = (strcmp (archive_name_array[0], dev_null) == 0
+  dev_null_output = (streq (archive_name_array[0], dev_null)
 		     || (! _isrmt (archive)
 			 && S_ISCHR (archive_stat.st_mode)
 			 && (dev_null_stat.st_ino != 0
@@ -383,7 +383,7 @@ sys_child_open_for_compress (void)
 
       /* We don't need a grandchild tar.  Open the archive and launch the
 	 compressor.  */
-      if (strcmp (archive_name_array[0], "-"))
+      if (!streq (archive_name_array[0], "-"))
 	{
 	  archive = creat (archive_name_array[0], MODE_RW);
 	  if (archive < 0)
@@ -425,7 +425,7 @@ sys_child_open_for_compress (void)
   xdup2 (child_pipe[PREAD], STDIN_FILENO);
   xclose (child_pipe[PWRITE]);
 
-  if (strcmp (archive_name_array[0], "-") == 0)
+  if (streq (archive_name_array[0], "-"))
     archive = STDOUT_FILENO;
   else
     {
@@ -553,7 +553,7 @@ sys_child_open_for_uncompress (void)
      b) the file is to be accessed by rmt: compressor doesn't know how;
      c) the file is not a plain file.  */
 
-  if (strcmp (archive_name_array[0], "-") != 0
+  if (!streq (archive_name_array[0], "-")
       && !_remdev (archive_name_array[0])
       && is_regular_file (archive_name_array[0]))
     {
@@ -593,7 +593,7 @@ sys_child_open_for_uncompress (void)
   xdup2 (child_pipe[PWRITE], STDOUT_FILENO);
   xclose (child_pipe[PREAD]);
 
-  if (strcmp (archive_name_array[0], "-") == 0)
+  if (streq (archive_name_array[0], "-"))
     archive = STDIN_FILENO;
   else
     archive = rmtopen (archive_name_array[0], O_RDONLY | O_BINARY,

src/tar.c

@@ -240,7 +240,7 @@ set_archive_format (char const *name)
 {
   struct fmttab const *p;
 
-  for (p = fmttab; strcmp (p->name, name) != 0; )
+  for (p = fmttab; !streq (p->name, name); )
     if (! (++p)->name)
       paxusage (_("%s: Invalid archive format"),
 		quotearg_colon (name));
@@ -336,7 +336,7 @@ static void
 tar_set_quoting_style (char *arg)
 {
   for (idx_t i = 0; quoting_style_args[i]; i++)
-    if (strcmp (arg, quoting_style_args[i]) == 0)
+    if (streq (arg, quoting_style_args[i]))
       {
 	set_quoting_style (NULL, i);
 	return;
@@ -1039,7 +1039,7 @@ optloc_eq (struct option_locus *a, struct option_locus *b)
   if (a->source == OPTS_COMMAND_LINE)
     return true;
   assume (a->name);
-  return strcmp (a->name, b->name) == 0;
+  return streq (a->name, b->name);
 }
 
 static void
@@ -1058,7 +1058,7 @@ set_use_compress_program_option (const char *string, struct option_locus *loc)
 {
   struct option_locus *p = optloc_save (OC_COMPRESS, loc);
   if (use_compress_program_option
-      && strcmp (use_compress_program_option, string) != 0
+      && !streq (use_compress_program_option, string)
       && p->source == OPTS_COMMAND_LINE)
     paxusage (_("Conflicting compression options"));
 
@@ -1112,7 +1112,7 @@ decode_signal (const char *name)
   if (strncmp (s, "SIG", 3) == 0)
     s += 3;
   for (struct sigtab const *p = sigtab; p < sigtab + nsigtab; p++)
-    if (strcmp (p->name, s) == 0)
+    if (streq (p->name, s))
       return p->signo;
   paxfatal (0, _("Unknown signal name: %s"), name);
 }
@@ -1180,7 +1180,7 @@ report_textual_dates (struct tar_args *args)
       if (verbose_option)
 	{
 	  char const *treated_as = tartime (p->ts, true);
-	  if (strcmp (p->date, treated_as) != 0)
+	  if (!streq (p->date, treated_as))
 	    paxwarn (0, _("Option %s: Treating date '%s' as %s"),
 		     p->option, p->date, treated_as);
 	}
@@ -2741,7 +2741,7 @@ decode_options (int argc, char **argv)
       if (!name_more_files ())
 	paxusage (_("Cowardly refusing to create an empty archive"));
       if (args.compress_autodetect && archive_names
-	  && strcmp (archive_name_array[0], "-"))
+	  && !streq (archive_name_array[0], "-"))
 	set_compression_program_by_suffix (archive_name_array[0],
 					   use_compress_program_option,
 					   true);
@@ -2754,7 +2754,7 @@ decode_options (int argc, char **argv)
       for (archive_name_cursor = archive_name_array;
 	   archive_name_cursor < archive_name_array + archive_names;
 	   archive_name_cursor++)
-	if (strcmp (*archive_name_cursor, "-") == 0)
+	if (streq (*archive_name_cursor, "-"))
 	  request_stdin ("-f");
       break;
 
@@ -2764,7 +2764,7 @@ decode_options (int argc, char **argv)
       for (archive_name_cursor = archive_name_array;
 	   archive_name_cursor < archive_name_array + archive_names;
 	   archive_name_cursor++)
-	if (strcmp (*archive_name_cursor, "-") == 0)
+	if (streq (*archive_name_cursor, "-"))
 	  paxusage (_("Options '-Aru' are incompatible with '-f -'"));
 
     default:

src/update.c

@@ -102,7 +102,7 @@ update_archive (void)
 
   name_gather ();
   open_archive (ACCESS_UPDATE);
-  acting_as_filter = strcmp (archive_name_array[0], "-") == 0;
+  acting_as_filter = streq (archive_name_array[0], "-");
   xheader_forbid_global ();
 
   while (!found_end)

src/warning.c

@@ -95,12 +95,12 @@ set_warning_option (const char *arg)
   bool negate = false;
   int option;
 
-  if (strcmp (arg, "none") == 0)
+  if (streq (arg, "none"))
     {
       warning_option = 0;
       return;
     }
-  if (strlen (arg) > 2 && memcmp (arg, "no-", 3) == 0)
+  if (strncmp (arg, "no-", 3) == 0)
     {
       negate = true;
       arg += 3;

src/xattrs.c

@@ -751,7 +751,7 @@ xattrs_xattrs_set (MAYBE_UNUSED struct tar_stat_info const *st,
              the first run except 'security.capability' which is restored in
              'later_run == 1'.  */
           if (typeflag == REGTYPE
-              && later_run == (strcmp (keyword, "security.capability") != 0))
+	      && streq (keyword, "security.capability") != later_run)
             continue;
 
           if (xattrs_masked_out (keyword, false /* extracting */ ))

src/xheader.c

@@ -124,7 +124,7 @@ xheader_keyword_override_p (const char *keyword)
   struct keyword_list *kp;
 
   for (kp = keyword_override_list; kp; kp = kp->next)
-    if (strcmp (kp->pattern, keyword) == 0)
+    if (streq (kp->pattern, keyword))
       return true;
   return false;
 }
@@ -201,19 +201,19 @@ xheader_set_keyword_equal (char *kw, char *eq)
   for (p = eq + 1; *p && c_isspace (*p); p++)
     ;
 
-  if (strcmp (kw, "delete") == 0)
+  if (streq (kw, "delete"))
     {
       if (xheader_protected_pattern_p (p))
 	paxusage (_("Pattern %s cannot be used"), quote (p));
       xheader_list_append (&keyword_pattern_list, p, NULL);
     }
-  else if (strcmp (kw, "exthdr.name") == 0)
+  else if (streq (kw, "exthdr.name"))
     assign_string (&exthdr_name, p);
-  else if (strcmp (kw, "globexthdr.name") == 0)
+  else if (streq (kw, "globexthdr.name"))
     assign_string (&globexthdr_name, p);
-  else if (strcmp (kw, "exthdr.mtime") == 0)
+  else if (streq (kw, "exthdr.mtime"))
     assign_time_option (&exthdr_mtime_option, &exthdr_mtime, p);
-  else if (strcmp (kw, "globexthdr.mtime") == 0)
+  else if (streq (kw, "globexthdr.mtime"))
     assign_time_option (&globexthdr_mtime_option, &globexthdr_mtime, p);
   else
     {
@@ -561,7 +561,7 @@ locate_handler (char const *keyword)
       }
     else
       {
-        if (strcmp (p->keyword, keyword) == 0)
+        if (streq (p->keyword, keyword))
           return p;
       }
 
@@ -587,7 +587,7 @@ xheader_protected_keyword_p (const char *keyword)
 
   for (p = xhdr_tab; p->keyword; p++)
     if (!p->prefix && (p->flags & XHDR_PROTECTED)
-        && strcmp (p->keyword, keyword) == 0)
+        && streq (p->keyword, keyword))
       return true;
   return false;
 }