diff options
author | Jim Meyering <jim@meyering.net> | 1995-09-19 14:30:59 +0000 |
---|---|---|
committer | Jim Meyering <jim@meyering.net> | 1995-09-19 14:30:59 +0000 |
commit | cf66a231db2fe413a214ea7e3753453c2016f68a (patch) | |
tree | d73277c8516848d4f4b0d94dadeea97562df5606 /lib/getline.c | |
parent | 4ad1794bf30e3b33f2501c9f1354c483b95ab008 (diff) | |
download | gnulib-cf66a231db2fe413a214ea7e3753453c2016f68a.tar.gz |
.
Diffstat (limited to 'lib/getline.c')
-rw-r--r-- | lib/getline.c | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/lib/getline.c b/lib/getline.c new file mode 100644 index 0000000000..c69946148f --- /dev/null +++ b/lib/getline.c @@ -0,0 +1,126 @@ +/* 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); +} |