Don't assume a huge stack.

lib/getline.cc

@@ -0,0 +1,118 @@
+/* getline.c -- Replacement for GNU C library function getline
+
+Copyright (C) 1993, 1996, 2001-2002 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 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. */
+
+/* Written by Jan Brittenson, bson@gnu.ai.mit.edu.  */
+
+/* Specification.  */
+#include "getline.h"
+
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+
+/* Always add at least this many bytes when extending the buffer.  */
+#define MIN_CHUNK 64
+
+/* Read up to (and including) a TERMINATOR from STREAM into *LINEPTR
+   + OFFSET (and null-terminate it). *LINEPTR is a pointer returned from
+   malloc (or NULL), pointing to *N characters of space.  It is realloc'd
+   as necessary.  Return the number of characters read (not including the
+   null terminator), or -1 on error or EOF.
+   NOTE: There is another getstr() function declared in <curses.h>.  */
+
+static int
+getstr (char **lineptr, size_t *n, FILE *stream, char terminator, size_t offset)
+{
+  size_t nchars_avail;          /* Allocated but unused chars in *LINEPTR.  */
+  char *read_pos;               /* Where we're reading into *LINEPTR. */
+
+  if (!lineptr || !n || !stream)
+    return -1;
+
+  if (!*lineptr)
+    {
+      *n = MIN_CHUNK;
+      *lineptr = new char[*n];
+    }
+
+  nchars_avail = *n - offset;
+  read_pos = *lineptr + offset;
+
+  for (;;)
+    {
+      register int c = getc (stream);
+
+      /* We always want at least one char left in the buffer, since we
+         always (unless we get an error while reading the first char)
+         NUL-terminate the line buffer.  */
+
+      assert (*n - nchars_avail == (size_t) (read_pos - *lineptr));
+      if (nchars_avail < 2)
+        {
+          if (*n > MIN_CHUNK)
+            *n *= 2;
+          else
+            *n += MIN_CHUNK;
+
+          nchars_avail = *n + *lineptr - read_pos;
+          char *new_line = new char[*n];
+          if (*lineptr)
+            {
+              memcpy (new_line, *lineptr, read_pos - *lineptr);
+              delete[] *lineptr;
+            }
+          *lineptr = new_line;
+          read_pos = *n - nchars_avail + *lineptr;
+          assert (*n - nchars_avail == (size_t) (read_pos - *lineptr));
+        }
+
+      if (c == EOF || ferror (stream))
+        {
+          /* Return partial line, if any.  */
+          if (read_pos == *lineptr)
+            return -1;
+          else
+            break;
+        }
+
+      *read_pos++ = c;
+      nchars_avail--;
+
+      if (c == terminator)
+        /* Return the line.  */
+        break;
+    }
+
+  /* Done - NUL terminate and return the number of chars read.  */
+  *read_pos = '\0';
+
+  return read_pos - (*lineptr + offset);
+}
+
+int
+get_line (char **lineptr, size_t *n, FILE *stream)
+{
+  return getstr (lineptr, n, stream, '\n', 0);
+}
+
+int
+get_delim (char **lineptr, size_t *n, int delimiter, FILE *stream)
+{
+  return getstr (lineptr, n, stream, delimiter, 0);
+}