I am facing the following  strange  behaviour of the pascal  'READLN()'  and
'READ()' functions on the MPE.

Problem description:
--------------------

There is a file whose  record size is greater than 255 bytes.  This file can
be of either fixed length or variable  length  record type.  Now a few lines
of text is added to this  file.  Some of  these  lines  have  more  than 254
characters in them.

Also there is a Pascal  program  which I have  written,  that is supposed to
open the above  mentioned  file for input and display  the  contents of that
file line by line  (ie.  record by  record)  and also the  total  number  of
characters in each line.

Now I am observing some strange or unexpected behaviour of this small pascal
program under the following instances of input file:

    1.  If a line in the input file has less than 254  characters,  then the
        behavior is correct and as expected.

    2.  If a line in the input file has more than 254  characters,  then the
        call to the pascal readln() function senses an end of line character
        after 254th  character  and is ignoring  the rest of the  characters
        from 255 till the end of that  record.  The  next  call to  readln()
        reads (at the most 254 chars) FROM THE BEGINNING OF THE NEXT RECORD.

        Even the behavior of the pascal function read() is the same as above.
        If there  are more than 254  characters  in a line of  record,  then
        after the 254th call to the read()  function  the eoln() is becoming
        true.

Any explaination for this strange behavior?


Following is the pascal program that I have written, to be executed on MPE:
--------------------------------------------------------------------------

program readGivenFile(input,output);

    procedure test;
        label
            9999;

        var
            nextChar, ic : char;
            tcc,lc : integer; {* tcc => total chars count, lc => line count *}
            inFile : text;
            inFileName : string[80];
    begin
        tcc := 0;
        lc := 1;

        writeln('Enter the name of FILE to read: ');
          write('                                ');
        readln(inFileName);
        writeln;

        reset(inFile, inFileName); {* open the file for reading *}

        {* WHILE not(eof(inFile)) DO BEGIN *}
        while(true) do begin
            if eof(inFile) then
                goto 9999;
            if eoln(inFile) then begin
                readln(inFile);
                writeln;
                writeln('Number of chars in line ', lc, ' = ', tcc);
                writeln;
                lc := lc+1;
                tcc := 0;
            end {IF}
            Else begin
                read(inFile, nextChar);
                write(nextChar);
                tcc := tcc+1;
            end; {Else}
        end; {WHILE}

        9999:
            close(inFile);
    end;

BEGIN
    test;
END.



Also I have coded the above pascal  program into an  equivalent  'C' program
and ran it on MPE.  This equivalent C program is working perfectly fine with
the results as expected!!

Following  is the equivalent 'C' code of the above program.
-----------------------------------------------------------
This  'C'  program  was also  executed  on the  MPE.  This  program  behaves
correctly and gives the expected results.


#include <stdio.h>

main(argc, argv)
int argc;
char* argv[];
{
    int tcc,lc,nextChar,ic;
    FILE *fp;

    if(argc != 2)
    {
        printf("Usage: %s <fileName>\n", argv[0]);
        exit(1);
    }

    if ( (fp = fopen(argv[1],"r")) == NULL )
    {
        perror("fopen");
        exit(1);
    }

    tcc=0;
    lc=1;

    while(1)
    {
        if( (nextChar = getc(fp)) == EOF)
            break;
        else
            fprintf(stdout,"%c",nextChar);

        if(nextChar == '\n')
        {
            fprintf(stdout,"Number of chars in line %d = %d\n\n", lc,tcc);
            lc++;
            tcc=0;
        }
        else
            tcc++;
    }

    fclose(fp);
}


Can anyone  explain for this behavior or suggest some solution or workaround
for this Pascal problem on MPE ??

---

Shivanand C. Hiremath
HP-ISO, Bangalore, India.
Email: <[log in to unmask]>,