Xi-Language Reference: General Functions

    • eof (End of File)
    • istream (Opens a file for reading)
    • listvariables (prints out all defined variables)
    • ostream (Opens a file for writing)
    • print (Prints one or more expressions)
    • printf (Formated output of one or more expressions)
    • sprintf (Formated output in a string)

    eof (End of File)

    Parameters

              eof ( istream )
    
              Types: istream                istream
    

    Return

              int  (-1, 0, > 0)
    

    Description

    The Function eof returns nonzero when the end of a file has been reached. Otherwise it returns zero. Minus one indicates an error.

    Example

     (  1)>s=istream("bla.out");
     (  2)>print(eof(s));
     <int> 0
    

    See also

    istream

    istream (Opens a file for reading)

    Parameters

              istream ( name, ascii = 0, bin = 0, fortran = 0 )
    
              Types: name                   string
                     ascii                  int
                     bin                    int
                     fortran                int
    

    Return

              istream  (Containing the intput stream)
    

    Description

    The istream opens a file name for reading if it exists. The flags ascii, bin and fortran have the same meaning as the corresponding flags of the ostream function.

    Example

     (  1)>s=istream("bla.out");
     (  2)>double arr[5,5];
     (  3)>s >> arr;
     (  4)>delete s;
     (  5)>print(arr);
     <dblarr>
                0            1            2            3            4 
                5            6            7            8            9 
               10           11           12           13           14 
               15           16           17           18           19 
               20           21           22           23           24 
    

    See also

    eof, ostream

    listvariables (prints out all defined variables)

    Parameters

              listvariables ( )
    

    Return

              -1
    

    Description

    The function listvariables prints out all defined variables.

    Example

     >double a=0, b=2;
     >char s;
     >listvaribles();
     a : <double>0
     b : <double>2
     s : Not defined yet
     0
    

    ostream (Opens a file for writing)

    Parameters

              ostream ( name, ascii = 0, bin = 0, fortran = 0 )
    
              Types: name                   string
                     ascii                  int
                     bin                    int
                     fortran                int
    

    Return

              ostream  (Containing the output stream)
    

    Description

    The ostream opens a file name for writing, if the file exists it will be erased, so be causious with this function. The ascii flag indicates that the file should be written in a readable format, i.e. numbers will be explicitly written and arrays are given in tabular order - of cause this costs a lot of memory. The bin indicates that the file should be written in binary (non-readable) format which is a lot faster and costs less memory than the ascii-format. The fortran is usefull if you want to write output that could be read by a fortran programm with the option unformatted. This format is not readable too.

    Example

     (  1)>s=ostream("bla.out");
     (  2)>arr=dincarr(5,5);
     (  3)>s << arr;
     (  4)>delete s;
     (  5)>$ cat bla.out
                0            1            2            3            4 
                5            6            7            8            9 
               10           11           12           13           14 
               15           16           17           18           19 
               20           21           22           23           24
    

    See also

    istream

    print (Prints one or more expressions)

    Parameters

              print ( arg... )
    
              Types: arg...                 Any
    

    Return

              -1
    

    Description

    The print function simply prints the result of an arbitrary number of expressions. In other words: First arg0 will be calculated then arg1 and so on. print explicitly prints the type of the results.

    Example

     (  1)>print(5+4,dincarr(10),"blabla");
     <int> 9
     <dblarr>
                0            1            2            3            4            5 
                6            7            8            9 
     <string> "blabla"
    

    printf (Formated output of one or more expressions)

    Parameters

              printf ( format, arg... )
    
              Types: format                 string
                     arg...                 Any
    

    Return

              -1
    

    Description

    The printf acts in the same way as the corresponding C function. For detailed information of the format-string's structure refer to a C-introduction.

    Example

     (  1)>printf("The Value of %s is %g\n","bla",5+4);
     The Value of bla is 9
    

    sprintf (Formated output in a string)

    Parameters

              sprintf ( format, arg... )
    
              Types: format                 string
                     arg...                 Any
    

    Return

              string  (containing the output)
    

    Description

    The sprintf acts in the same way as the printf with the only difference that the output is not printed on the console but is stored in a string. Note that the Xi version of sprintf has a slightly different calling sceem than the coresponding C function.

    Example

     (  1)>a=sprintf("The Value of %s is %g","bla",5+4);
     (  2)>print(a);
     <string> "The Value of bla is 9"
    

    See also

    printf
    © 1995 by Bodo Junglas, Klaus Spanderen and Fabian Weis
    - Last revised: Wed Jun 19 16:58:32 1996