pd.if.org Git - pdclib/blob - functions/stdio/_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 #include <_PDCLIB_io.h>
  13 /* Helper function that parses the C-style mode string passed to fopen() into
  14    the PDCLib flags FREAD, FWRITE, FAPPEND, FRW (read-write) and FBIN (binary
  15    mode).
  16 */
  17 unsigned int _PDCLIB_filemode( char const * const mode )
  18 {
  19     if(!mode) return 0;
  20
  21     unsigned rc = 0;
  22     switch ( mode[0] )
  23     {
  24         case 'r':
  25             rc |= _PDCLIB_FREAD;
  26             break;
  27         case 'w':
  28             rc |= _PDCLIB_FWRITE;
  29             break;
  30         case 'a':
  31             rc |= _PDCLIB_FAPPEND | _PDCLIB_FWRITE;
  32             break;
  33         default:
  34             /* Other than read, write, or append - invalid */
  35             return 0;
  36     }
  37     for ( size_t i = 1; i < 4; ++i )
  38     {
  39         switch ( mode[i] )
  40         {
  41             case '+':
  42                 if ( rc & _PDCLIB_FRW ) return 0; /* Duplicates are invalid */
  43                 rc |= _PDCLIB_FRW;
  44                 break;
  45             case 'b':
  46                 if ( rc & _PDCLIB_FBIN ) return 0; /* Duplicates are invalid */
  47                 rc |= _PDCLIB_FBIN;
  48                 break;
  49             case '\0':
  50                 /* End of mode */
  51                 return rc;
  52             default:
  53                 /* Other than read/write or binary - invalid. */
  54                 return 0;
  55         }
  56     }
  57     /* Longer than three chars - invalid. */
  58     return 0;
  59 }
  60 #endif
  61
  62 #ifdef TEST
  63 #include <_PDCLIB_test.h>
  64
  65 int main( void )
  66 {
  67 #ifndef REGTEST
  68     TESTCASE( _PDCLIB_filemode( "r" ) == _PDCLIB_FREAD );
  69     TESTCASE( _PDCLIB_filemode( "w" ) == _PDCLIB_FWRITE );
  70     TESTCASE( _PDCLIB_filemode( "a" ) == ( _PDCLIB_FAPPEND | _PDCLIB_FWRITE ) );
  71     TESTCASE( _PDCLIB_filemode( "r+" ) == ( _PDCLIB_FREAD | _PDCLIB_FRW ) );
  72     TESTCASE( _PDCLIB_filemode( "w+" ) == ( _PDCLIB_FWRITE | _PDCLIB_FRW ) );
  73     TESTCASE( _PDCLIB_filemode( "a+" ) == ( _PDCLIB_FAPPEND | _PDCLIB_FWRITE | _PDCLIB_FRW ) );
  74     TESTCASE( _PDCLIB_filemode( "rb" ) == ( _PDCLIB_FREAD | _PDCLIB_FBIN ) );
  75     TESTCASE( _PDCLIB_filemode( "wb" ) == ( _PDCLIB_FWRITE | _PDCLIB_FBIN ) );
  76     TESTCASE( _PDCLIB_filemode( "ab" ) == ( _PDCLIB_FAPPEND | _PDCLIB_FWRITE | _PDCLIB_FBIN ) );
  77     TESTCASE( _PDCLIB_filemode( "r+b" ) == ( _PDCLIB_FREAD | _PDCLIB_FRW | _PDCLIB_FBIN ) );
  78     TESTCASE( _PDCLIB_filemode( "w+b" ) == ( _PDCLIB_FWRITE | _PDCLIB_FRW | _PDCLIB_FBIN ) );
  79     TESTCASE( _PDCLIB_filemode( "a+b" ) == ( _PDCLIB_FAPPEND | _PDCLIB_FWRITE | _PDCLIB_FRW | _PDCLIB_FBIN ) );
  80     TESTCASE( _PDCLIB_filemode( "rb+" ) == ( _PDCLIB_FREAD | _PDCLIB_FRW | _PDCLIB_FBIN ) );
  81     TESTCASE( _PDCLIB_filemode( "wb+" ) == ( _PDCLIB_FWRITE | _PDCLIB_FRW | _PDCLIB_FBIN ) );
  82     TESTCASE( _PDCLIB_filemode( "ab+" ) == ( _PDCLIB_FAPPEND | _PDCLIB_FWRITE | _PDCLIB_FRW | _PDCLIB_FBIN ) );
  83     TESTCASE( _PDCLIB_filemode( "x" ) == 0 );
  84     TESTCASE( _PDCLIB_filemode( "r++" ) == 0 );
  85     TESTCASE( _PDCLIB_filemode( "wbb" ) == 0 );
  86     TESTCASE( _PDCLIB_filemode( "a+bx" ) == 0 );
  87 #endif
  88     return TEST_RESULTS;
  89 }
  90
  91 #endif
  92