Book a Demo!
CoCalc Logo Icon
StoreFeaturesDocsShareSupportNewsAboutPoliciesSign UpSign In
alexbevi
GitHub Repository: alexbevi/BizHawk
 Path: blob/master/waterbox/libc/functions/stdio/fseek.c
2 views
1
/* fseek( FILE *, long, int )

2


3
   This file is part of the Public Domain C Library (PDCLib).

4
   Permission is granted to use, modify, and / or redistribute at will.

5
*/

6


7
#include <stdio.h>

8


9
#ifndef REGTEST

10
#include "_PDCLIB_io.h"

11


12
int _PDCLIB_fseek_unlocked( FILE * stream, long loffset, int whence )

13
{

14
    _PDCLIB_int64_t offset = loffset;

15
    if ( stream->status & _PDCLIB_FWRITE )

16
    {

17
        if ( _PDCLIB_flushbuffer( stream ) == EOF )

18
        {

19
            return EOF;

20
        }

21
    }

22
    stream->status &= ~ _PDCLIB_EOFFLAG;

23
    if ( stream->status & _PDCLIB_FRW )

24
    {

25
        stream->status &= ~ ( _PDCLIB_FREAD | _PDCLIB_FWRITE );

26
    }

27


28
    if ( whence == SEEK_CUR )

29
    {

30
        whence  = SEEK_SET;

31
        offset += _PDCLIB_ftell64_unlocked( stream );

32
    }

33


34
    return ( _PDCLIB_seek( stream, offset, whence ) != EOF ) ? 0 : EOF;

35
}

36


37
int fseek( FILE * stream, long loffset, int whence )

38
{

39
    _PDCLIB_flockfile( stream );

40
    int r = _PDCLIB_fseek_unlocked( stream, loffset, whence );

41
    _PDCLIB_funlockfile( stream );

42
    return r;

43
}

44


45
#endif

46


47
#ifdef TEST

48
#include "_PDCLIB_test.h"

49
#include <string.h>

50


51
int main( void )

52
{

53
    FILE * fh;

54
    TESTCASE( ( fh = tmpfile() ) != NULL );

55
    TESTCASE( fwrite( teststring, 1, strlen( teststring ), fh ) == strlen( teststring ) );

56
    /* General functionality */

57
    TESTCASE( fseek( fh, -1, SEEK_END ) == 0  );

58
    TESTCASE( (size_t)ftell( fh ) == strlen( teststring ) - 1 );

59
    TESTCASE( fseek( fh, 0, SEEK_END ) == 0 );

60
    TESTCASE( (size_t)ftell( fh ) == strlen( teststring ) );

61
    TESTCASE( fseek( fh, 0, SEEK_SET ) == 0 );

62
    TESTCASE( ftell( fh ) == 0 );

63
    TESTCASE( fseek( fh, 5, SEEK_CUR ) == 0 );

64
    TESTCASE( ftell( fh ) == 5 );

65
    TESTCASE( fseek( fh, -3, SEEK_CUR ) == 0 );

66
    TESTCASE( ftell( fh ) == 2 );

67
    /* Checking behaviour around EOF */

68
    TESTCASE( fseek( fh, 0, SEEK_END ) == 0 );

69
    TESTCASE( ! feof( fh ) );

70
    TESTCASE( fgetc( fh ) == EOF );

71
    TESTCASE( feof( fh ) );

72
    TESTCASE( fseek( fh, 0, SEEK_END ) == 0 );

73
    TESTCASE( ! feof( fh ) );

74
    /* Checking undo of ungetc() */

75
    TESTCASE( fseek( fh, 0, SEEK_SET ) == 0 );

76
    TESTCASE( fgetc( fh ) == teststring[0] );

77
    TESTCASE( fgetc( fh ) == teststring[1] );

78
    TESTCASE( fgetc( fh ) == teststring[2] );

79
    TESTCASE( ftell( fh ) == 3 );

80
    TESTCASE( ungetc( teststring[2], fh ) == teststring[2] );

81
    TESTCASE( ftell( fh ) == 2 );

82
    TESTCASE( fgetc( fh ) == teststring[2] );

83
    TESTCASE( ftell( fh ) == 3 );

84
    TESTCASE( ungetc( 'x', fh ) == 'x' );

85
    TESTCASE( ftell( fh ) == 2 );

86
    TESTCASE( fgetc( fh ) == 'x' );

87
    TESTCASE( ungetc( 'x', fh ) == 'x' );

88
    TESTCASE( ftell( fh ) == 2 );

89
    TESTCASE( fseek( fh, 2, SEEK_SET ) == 0 );

90
    TESTCASE( fgetc( fh ) == teststring[2] );

91
    /* PDCLIB-7: Check that we handle the underlying file descriptor correctly

92
     *           in the SEEK_CUR case */

93
    TESTCASE( fseek( fh, 10, SEEK_SET ) == 0 );

94
    TESTCASE( ftell( fh ) == 10l );

95
    TESTCASE( fseek( fh, 0, SEEK_CUR ) == 0 );

96
    TESTCASE( ftell( fh ) == 10l );

97
    TESTCASE( fseek( fh, 2, SEEK_CUR ) == 0 );

98
    TESTCASE( ftell( fh ) == 12l );

99
    TESTCASE( fseek( fh, -1, SEEK_CUR ) == 0 );

100
    TESTCASE( ftell( fh ) == 11l );

101
    /* Checking error handling */

102
    TESTCASE( fseek( fh, -5, SEEK_SET ) == -1 );

103
    TESTCASE( fseek( fh, 0, SEEK_END ) == 0 );

104
    TESTCASE( fclose( fh ) == 0 );

105
    return TEST_RESULTS;

106
}

107


108
#endif

109


110


111