[SOLVED] carriage return by fgets

carriage return by fgets

I am running the following code:

#include<stdio.h>
#include<string.h>
#include<io.h>

int main(){
    FILE *fp;
    if((fp=fopen("test.txt","r"))==NULL){
        printf("File can't be read\n");
        exit(1);
    }
    char str[50];
    fgets(str,50,fp);
    printf("%s",str);
    return 0;
}

text.txt contains: I am a boy\r\n

Since I am on Windows, it takes \r\n as a new line character and so if I read this from a file it should store "I am a boy\n\0" in str, but I get "I am a boy\r\n". I am using mingw compiler.

Solution

Since I am on Windows, it takes \r\n as a new line character...

This assumption is wrong. The C standard treats carriage return and new line as two different things, as evidenced in C99 §5.2.1/3 (Character sets):

[...] In the basic execution character set, there shall be control characters representing alert, backspace, carriage return, and new-line. [...]

The fgets function description is as follows, in C99 §7.19.7.2/2:

The fgets function reads at most one less than the number of characters specified by n from the stream pointed to by stream into the array pointed to by s. No additional characters are read after a new-line character (which is retained) or after end-of-file. A null character is written immediately after the last character read into the array.

Therefore, when encountering the string I am a boy\r\n, a conforming implementation should read up to the \n character. There is no possibly sane reason why the implementation should discard \r based on the platform.