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- // SPDX-License-Identifier: GPL-2.0+
- /* getline.c -- Replacement for GNU C library function getline
- *
- * Copyright (C) 1993, 1996, 2001, 2002 Free Software Foundation, Inc.
- */
- /* 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);
- }
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