CITS2002 Systems Programming  
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Trimming end-of-line characters from a line

To make future examples easy to read, we'll write a function, named trim_line(), that receives a line (a character array) as a parameter, and "removes" the first carriage-return or newline character that it finds.

It's very similar to functions like my_strlen() that we've written in laboratory work: 


//  REMOVE ANY TRAILING end-of-line CHARACTERS FROM THE LINE
void trim_line(char line[])
{
    int i = 0;

//  LOOP UNTIL WE REACH THE END OF line
    while(line[i] != '\0') {

//  CHECK FOR CARRIAGE-RETURN OR NEWLINE
        if( line[i] == '\r' || line[i] == '\n' ) {
            line[i] = '\0'; // overwrite with null-byte
            break;          // leave the loop early
        }
        i = i+1;            // iterate through character array
    }
}

We note:

  • we simply overwrite the unwanted character with the null-byte.
  • the function will actually modify the caller's copy of the variable.
  • we do not return any value.

 

CITS2002 Systems Programming, Lecture 8, p7, 15th August 2023.