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Question

I'm trying to read from a file in C as a part of a project of mine.

My PURPOSE is to parse the words in that file(which are either separated by a whitespace, comma, semicolon or the new line character) into tokens.

For that I MUST read character by character.

do {

    do {

        tempChar = fgetc(asmCode);
        strcpy(&tempToken[i], &tempChar);

        i++;

    } while (tempChar != ' ' || tempChar != ':' || tempChar != ';' || tempChar != ',' || tempChar != '\n');//reading until the given parameters

    i = 0;

    //some other code with some other purpose

} while (tempChar != EOF);//reading until the end of the file

Even though the following code reads from the file, it doesn't stop reading since somehow it doesn't apply the conditions inside while.

What am I doing wrong here?

PS both tempChar & tempToken are defined as char variables. also another

Answer 1

I guess something is going wrong with this line of code:

while (tempChar != ' ' || tempChar != ':' || tempChar != ';' || tempChar != ',' || tempChar != '\\n');

Since you used ||, the condition is always true, making it an infinity loop. Try this, this may work:

while (tempChar != ' ' && tempChar != ':' && tempChar != ';' && tempChar != ',' && tempChar != '\\n');

Also, I prefer if(feof(asmCode)) over if (tempChar == EOF) . In case the the value tempChar is same as EOF, if (tempChar == EOF) will not work.

Answer 2

as I see in your code the type of tempchar is char: char tempchar

you can not use strcpy(&tempToken[i], &tempChar); to copy char. the strcpy copy string to a sting buffer.

try the following fixed code

do {

    do {

        tempChar = fgetc(asmCode);

        if (tempChar == EOF)
            break;
        tempToken[i]= tempChar;

        i++;

    } while (tempChar != ' ' || tempChar != ':' || tempChar != ';' || tempChar != ',' || tempChar != '\n');//reading until the given parameters
    tempToken[i]='0';
    i = 0;  // this will erase the old content of tempToken !!! what are you trying to do here ?

    //some other code with some other purpose

} while (tempChar != EOF);//reading until the end of the file