78 lines
2.8 KiB
C
Executable File
78 lines
2.8 KiB
C
Executable File
/* A string or file based input stream.
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Copyright (C) 2024 Free Software Foundation, Inc.
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This file is free software: you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as
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published by the Free Software Foundation, either version 3 of the
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License, or (at your option) any later version.
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This file is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with this program. If not, see <https://www.gnu.org/licenses/>. */
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/* Written by Bruno Haible <bruno@clisp.org>, 2024. */
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#ifndef _SF_ISTREAM_H
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#define _SF_ISTREAM_H
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#include <stdio.h>
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#include "string-desc.h"
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/* An input stream type that can read from a file or from a string. */
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typedef struct sf_istream sf_istream_t;
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struct sf_istream
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{
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/* The input file stream, when reading from a file. */
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FILE *fp;
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/* The input area, when reading from a string. */
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const char *input;
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const char *input_end;
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};
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#ifdef __cplusplus
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extern "C" {
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#endif
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/* Initializes STREAM to read from FP.
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FP must be a FILE stream open for reading. */
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extern void sf_istream_init_from_file (sf_istream_t *stream, FILE *fp);
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/* Initializes STREAM to read from a NUL-terminated string INPUT.
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The contents of INPUT must stay available and unchanged as long as STREAM
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is in use. */
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extern void sf_istream_init_from_string (sf_istream_t *stream,
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const char *input);
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/* Initializes STREAM to read from a string INPUT.
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The contents of INPUT must stay available and unchanged as long as STREAM
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is in use. Operations on STREAM will not modify the contents of INPUT. */
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extern void sf_istream_init_from_string_desc (sf_istream_t *stream,
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string_desc_t input);
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/* Reads a single 'char' from STREAM, and returns it as an 'unsigned char'.
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Returns EOF when the end of stream was already reached. */
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extern int sf_getc (sf_istream_t *stream);
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/* Tests whether STREAM has encountered an error.
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You may want to call this function after sf_getc (stream) has
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returned EOF; in other situations it is guaranteed to return 0. */
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extern int sf_ferror (sf_istream_t *stream);
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/* Assuming that C was the last value returned by sf_getc (stream),
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this call pushes back C onto the stream.
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Only 1 character of pushback is guaranteed. */
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extern void sf_ungetc (sf_istream_t *stream, int c);
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/* Frees all memory held by STREAM.
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This call has no effect on the arguments provided to sf_istream_init_*. */
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extern void sf_free (sf_istream_t *stream);
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#ifdef __cplusplus
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}
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#endif
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#endif /* _SF_ISTREAM_H */
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