Merge from coreutils.

[gnulib.git] / lib / readtokens0.c

diff --git a/lib/readtokens0.c b/lib/readtokens0.c
new file mode 100644 (file)
index 0000000..b46ba8f
--- /dev/null
+++ b/lib/readtokens0.c
@@ -0,0 +1,98 @@
+/* readtokens0.c -- Read NUL-separated tokens from an input stream.
+   Copyright (C) 2004 Free Software Foundation, Inc.
+
+   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.
+
+   Written by Jim Meyering. */
+
+#include <config.h>
+#include <stdlib.h>
+
+#include "readtokens0.h"
+
+#define obstack_chunk_alloc malloc
+#define obstack_chunk_free free
+
+void
+readtokens0_init (struct Tokens *t)
+{
+  t->n_tok = 0;
+  t->tok = NULL;
+  t->tok_len = NULL;
+  obstack_init (&t->o_data);
+  obstack_init (&t->o_tok);
+  obstack_init (&t->o_tok_len);
+}
+
+void
+readtokens0_free (struct Tokens *t)
+{
+  obstack_free (&t->o_data, NULL);
+  obstack_free (&t->o_tok, NULL);
+  obstack_free (&t->o_tok_len, NULL);
+}
+
+/* Finalize (in the obstack_finish sense) the current token
+   and record its pointer and length.  */
+static void
+save_token (struct Tokens *t)
+{
+  /* Don't count the trailing NUL byte in the length.  */
+  size_t len = obstack_object_size (&t->o_data) - 1;
+  char const *s = obstack_finish (&t->o_data);
+  obstack_ptr_grow (&t->o_tok, s);
+  obstack_grow (&t->o_tok_len, &len, sizeof len);
+  t->n_tok++;
+}
+
+/* Read NUL-separated tokens from stream IN into T until EOF or error.
+   The final NUL is optional.  Always append a NULL pointer to the
+   resulting list of token pointers, but that pointer isn't counted
+   via t->n_tok.  Return true if successful.  */
+bool
+readtokens0 (FILE *in, struct Tokens *t)
+{
+
+  while (1)
+    {
+      int c = fgetc (in);
+      if (c == EOF)
+       {
+         size_t len = obstack_object_size (&t->o_data);
+         /* If the current object has nonzero length, then there
+            was no NUL byte at EOF -- or maybe there was an error,
+            in which case, we need to append a NUL byte to our buffer.  */
+         if (len)
+           {
+             obstack_1grow (&t->o_data, '\0');
+             save_token (t);
+           }
+
+         break;
+       }
+
+      obstack_1grow (&t->o_data, c);
+      if (c == '\0')
+       save_token (t);
+    }
+
+  /* Add a NULL pointer at the end, in case the caller (like du)
+     requires an argv-style array of strings.  */
+  obstack_ptr_grow (&t->o_tok, NULL);
+
+  t->tok = obstack_finish (&t->o_tok);
+  t->tok_len = obstack_finish (&t->o_tok_len);
+  return ! ferror (in);
+}