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Diffstat (limited to 'tools/getline.c')
-rw-r--r-- | tools/getline.c | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/tools/getline.c b/tools/getline.c new file mode 100644 index 0000000..3ba52a3 --- /dev/null +++ b/tools/getline.c @@ -0,0 +1,101 @@ +/* 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. */ + +#include <assert.h> +#include <stdio.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) +{ + 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 (char **lineptr, size_t *n, FILE *stream) +{ + return getstr(lineptr, n, stream, '\n', 0); +} |