pd.if.org Git - pdclib/blob - functions/_PDCLIB/filemode.c

   1 /* $Id$ */
   2
   3 /* _PDCLIB_filemode( const char * )
   4
   5    This file is part of the Public Domain C Library (PDCLib).
   6    Permission is granted to use, modify, and / or redistribute at will.
   7 */
   8
   9 #include <stddef.h>
  10
  11 #ifndef REGTEST
  12 /* Helper function that parses the C-style mode string passed to fopen() into
  13    the PDCLib flags FREAD, FWRITE, FAPPEND, FRW (read-write) and FBIN (binary
  14    mode).
  15 */
  16 unsigned int _PDCLIB_filemode( char const * const mode )
  17 {
  18     if(!mode) return 0;
  19
  20     unsigned rc = 0;
  21     switch ( mode[0] )
  22     {
  23         case 'r':
  24             rc |= _PDCLIB_FREAD;
  25             break;
  26         case 'w':
  27             rc |= _PDCLIB_FWRITE;
  28             break;
  29         case 'a':
  30             rc |= _PDCLIB_FAPPEND | _PDCLIB_FWRITE;
  31             break;
  32         default:
  33             /* Other than read, write, or append - invalid */
  34             return 0;
  35     }
  36     for ( size_t i = 1; i < 4; ++i )
  37     {
  38         switch ( mode[i] )
  39         {
  40             case '+':
  41                 if ( rc & _PDCLIB_FRW ) return 0; /* Duplicates are invalid */
  42                 rc |= _PDCLIB_FRW;
  43                 break;
  44             case 'b':
  45                 if ( rc & _PDCLIB_FBIN ) return 0; /* Duplicates are invalid */
  46                 rc |= _PDCLIB_FBIN;
  47                 break;
  48             case '\0':
  49                 /* End of mode */
  50                 return rc;
  51             default:
  52                 /* Other than read/write or binary - invalid. */
  53                 return 0;
  54         }
  55     }
  56     /* Longer than three chars - invalid. */
  57     return 0;
  58 }
  59 #endif
  60
  61 #ifdef TEST
  62 #include <_PDCLIB_test.h>
  63
  64 int main( void )
  65 {
  66 #ifndef REGTEST
  67     TESTCASE( _PDCLIB_filemode( "r" ) == _PDCLIB_FREAD );
  68     TESTCASE( _PDCLIB_filemode( "w" ) == _PDCLIB_FWRITE );
  69     TESTCASE( _PDCLIB_filemode( "a" ) == ( _PDCLIB_FAPPEND | _PDCLIB_FWRITE ) );
  70     TESTCASE( _PDCLIB_filemode( "r+" ) == ( _PDCLIB_FREAD | _PDCLIB_FRW ) );
  71     TESTCASE( _PDCLIB_filemode( "w+" ) == ( _PDCLIB_FWRITE | _PDCLIB_FRW ) );
  72     TESTCASE( _PDCLIB_filemode( "a+" ) == ( _PDCLIB_FAPPEND | _PDCLIB_FWRITE | _PDCLIB_FRW ) );
  73     TESTCASE( _PDCLIB_filemode( "rb" ) == ( _PDCLIB_FREAD | _PDCLIB_FBIN ) );
  74     TESTCASE( _PDCLIB_filemode( "wb" ) == ( _PDCLIB_FWRITE | _PDCLIB_FBIN ) );
  75     TESTCASE( _PDCLIB_filemode( "ab" ) == ( _PDCLIB_FAPPEND | _PDCLIB_FWRITE | _PDCLIB_FBIN ) );
  76     TESTCASE( _PDCLIB_filemode( "r+b" ) == ( _PDCLIB_FREAD | _PDCLIB_FRW | _PDCLIB_FBIN ) );
  77     TESTCASE( _PDCLIB_filemode( "w+b" ) == ( _PDCLIB_FWRITE | _PDCLIB_FRW | _PDCLIB_FBIN ) );
  78     TESTCASE( _PDCLIB_filemode( "a+b" ) == ( _PDCLIB_FAPPEND | _PDCLIB_FWRITE | _PDCLIB_FRW | _PDCLIB_FBIN ) );
  79     TESTCASE( _PDCLIB_filemode( "rb+" ) == ( _PDCLIB_FREAD | _PDCLIB_FRW | _PDCLIB_FBIN ) );
  80     TESTCASE( _PDCLIB_filemode( "wb+" ) == ( _PDCLIB_FWRITE | _PDCLIB_FRW | _PDCLIB_FBIN ) );
  81     TESTCASE( _PDCLIB_filemode( "ab+" ) == ( _PDCLIB_FAPPEND | _PDCLIB_FWRITE | _PDCLIB_FRW | _PDCLIB_FBIN ) );
  82     TESTCASE( _PDCLIB_filemode( "x" ) == 0 );
  83     TESTCASE( _PDCLIB_filemode( "r++" ) == 0 );
  84     TESTCASE( _PDCLIB_filemode( "wbb" ) == 0 );
  85     TESTCASE( _PDCLIB_filemode( "a+bx" ) == 0 );
  86 #endif
  87     return TEST_RESULTS;
  88 }
  89
  90 #endif
  91