gistfile1.c

    /*******************************************************************************
     * urlde.c
     * Commandline URL decode - fast and dirty
     * by tovis 2011
     * Build: make urlde and strip urlde
     * Usage: cat or echo "url coded text" | urlde
    *******************************************************************************/
    #include <stdlib.h>
    #include <stdio.h>
    #include <string.h>
    #include <ctype.h>
     
    //******************************************************************************
    int                     main(int c,char *argv[])
    {
      int           ichr = 0;
      char          shex[3];
      //... code ...
      do
      {
        ichr = getchar();
        switch ( ichr )
        {
        case '+':
          ichr = ' ';
          break;
        case '%':
          ichr = getchar();
          if ( ichr != '%' )
          {
            memset(shex,0,sizeof(shex));
            shex[0] = (char)ichr;
            shex[1] = (char)getchar();
            if ( !isxdigit(shex[0]) || !isxdigit(shex[1]) )
              ichr = '?';
            else
            {
              ichr  = 0;
              ichr  = ( shex[0] > 0x39 ) ? (shex[0] - 0x37 ) : (shex[0] - 0x30 );
              ichr  = ichr << 4;
              ichr += ( shex[1] > 0x39 ) ? (shex[1] - 0x37 ) : (shex[1] - 0x30 );
              if ( ichr == '\n' )
              {
                putchar(ichr);
                ichr = 0;
                continue;
              }
            }
          }
          break;
        default:
          break;
        }
        putchar(ichr);
      } while ( ichr != '\n' );
      exit ( 0 );
    } //end main
     
    /*******************************************************************************
     * end urlde.c
    *******************************************************************************/