123 lines
1.9 KiB
C
123 lines
1.9 KiB
C
/*
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* libifupdown/fgetline.c
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* Purpose: portable fgetline(3)
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*
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* Copyright (c) 2020 Ariadne Conill <ariadne@dereferenced.org>
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*
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* Permission to use, copy, modify, and/or distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* This software is provided 'as is' and without any warranty, express or
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* implied. In no event shall the authors be liable for any damages arising
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* from the use of this software.
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*/
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#include <stdbool.h>
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#include <stddef.h>
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#include <stdio.h>
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#include "libifupdown/fgetline.h"
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char *
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lif_fgetline(char *line, size_t size, FILE *stream)
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{
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char *s = line;
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char *end = line + size - 2;
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bool quoted = false;
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int c = '\0', c2;
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if (s == NULL)
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return NULL;
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while (s < end && (c = getc(stream)) != EOF)
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{
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if (c == '\\' && !quoted)
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{
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quoted = true;
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continue;
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}
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else if (c == '#')
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{
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if (!quoted) {
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/* Skip the rest of the line */
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do {
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c = getc(stream);
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} while (c != '\n' && c != EOF);
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*s++ = c;
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break;
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}
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quoted = false;
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continue;
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}
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else if (c == '\n')
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{
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if (quoted)
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{
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/* Trim spaces */
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do {
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c2 = getc(stream);
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} while (c2 == '\t' || c2 == ' ');
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ungetc(c2, stream);
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quoted = false;
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continue;
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}
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else
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{
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*s++ = c;
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}
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break;
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}
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else if (c == '\r')
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{
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*s++ = '\n';
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if ((c2 = getc(stream)) == '\n')
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{
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if (quoted)
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{
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quoted = false;
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continue;
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}
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break;
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}
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ungetc(c2, stream);
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if (quoted)
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{
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quoted = false;
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continue;
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}
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break;
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}
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else
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{
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if (quoted) {
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*s++ = '\\';
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quoted = false;
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}
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*s++ = c;
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}
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}
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if (c == EOF && (s == line || ferror(stream)))
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return NULL;
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*s = '\0';
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/* Remove newline character. */
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if (s > line && *(--s) == '\n') {
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*s = '\0';
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if (s > line && *(--s) == '\r')
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*s = '\0';
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}
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return line;
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}
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