pd.if.org Git - pdclib/blob - functions/stdio/_PDCLIB_filemode.c

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