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authorJim Meyering <jim@meyering.net>1995-09-19 14:30:59 +0000
committerJim Meyering <jim@meyering.net>1995-09-19 14:30:59 +0000
commitcf66a231db2fe413a214ea7e3753453c2016f68a (patch)
treed73277c8516848d4f4b0d94dadeea97562df5606 /lib/getline.c
parent4ad1794bf30e3b33f2501c9f1354c483b95ab008 (diff)
downloadgnulib-cf66a231db2fe413a214ea7e3753453c2016f68a.tar.gz
.
Diffstat (limited to 'lib/getline.c')
-rw-r--r--lib/getline.c126
1 files changed, 126 insertions, 0 deletions
diff --git a/lib/getline.c b/lib/getline.c
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+++ b/lib/getline.c
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+/* getline.c -- Replacement for GNU C library function getline
+
+Copyright (C) 1993 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., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+/* Written by Jan Brittenson, bson@gnu.ai.mit.edu. */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <sys/types.h>
+#include <stdio.h>
+#define NDEBUG
+#include <assert.h>
+
+#if STDC_HEADERS
+#include <stdlib.h>
+#else
+char *malloc (), *realloc ();
+#endif
+
+/* 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. */
+
+int
+getstr (lineptr, n, stream, terminator, offset)
+ char **lineptr;
+ size_t *n;
+ FILE *stream;
+ char terminator;
+ int offset;
+{
+ int nchars_avail; /* Allocated but unused chars in *LINEPTR. */
+ char *read_pos; /* Where we're reading into *LINEPTR. */
+ int ret;
+
+ if (!lineptr || !n || !stream)
+ return -1;
+
+ if (!*lineptr)
+ {
+ *n = MIN_CHUNK;
+ *lineptr = malloc (*n);
+ if (!*lineptr)
+ return -1;
+ }
+
+ 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 == read_pos - *lineptr);
+ if (nchars_avail < 2)
+ {
+ if (*n > MIN_CHUNK)
+ *n *= 2;
+ else
+ *n += MIN_CHUNK;
+
+ nchars_avail = *n + *lineptr - read_pos;
+ *lineptr = realloc (*lineptr, *n);
+ if (!*lineptr)
+ return -1;
+ read_pos = *n - nchars_avail + *lineptr;
+ assert(*n - nchars_avail == 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';
+
+ ret = read_pos - (*lineptr + offset);
+ return ret;
+}
+
+int
+getline (lineptr, n, stream)
+ char **lineptr;
+ size_t *n;
+ FILE *stream;
+{
+ return getstr (lineptr, n, stream, '\n', 0);
+}