strrev function inserts a line feed character in the first element of a string array

Question

So basically:

#include <stdio.h>
#include <conio.h>
#include <stdlib.h>
#include <string.h>

int main(void){
    //test strrev
    char s[50];
    char s2[50];
    char *ps;
    int i=0;
    printf("String to reverse: ");
    fgets(s,50,stdin);
    ps=strrev(s);
    strcpy(s2,ps); //copy contents to a string array
    //i did the copy because using printf("%s", ps); did the same thing

    printf("Reversed string: %s\n", s2); //PECULIAR, s2 enters line feed char in s2[0]

    //test loop to determine the inserted character
    while(1){
        if(s2[i]==10) {printf("is 10,%d", i); break;}; //the proof of LF
        if(s2[i]==12) {printf("is 12"); break;};
        if(s2[i]==13) {printf("is 13"); break;};
        if(s2[i]==15) {printf("is 15"); break;};
        i++;
    }
    for(i=0;i<50;i++){ //determine where the characters are positioned
        printf("%c: %d\n", s2[i], s2[i]);
        if(s2[i]=='\0') break;
    }

    system("PAUSE");
    return 0;
}

By running this program and entering the string....let's say "darts" will reverse the string in the array that will have the elements s2[0]='\012'=10(decimal), ...strad..., s2[7]='\0'. Is it normal for strrev to behave as such?

Answer 1

fgets stores the newline in the string. So when you strrev, \n (linefeed) will be the first element.

The fgets() function shall read bytes from stream into the array pointed to by s, until n-1 bytes are read, or a is read and transferred to s.

EDIT

Just tested it on Visual Studio:

char a[] = "abcd\n";
strrev(a);

printf("%d\n", a[0]); /* 10 */