#include <stdio.h>
#include <string.h>
/**
* Splits a string by newline characters and processes each line
* without modifying the original string (non-destructive).
*
* @param str The null-terminated input string to split.
*/
void split_by_newline(const char *str) {
// Guard clause: check for NULL pointer input
if (str == NULL) {
return;
}
const char *start = str;
const char *end = NULL;
int line_num = 1;
// Iterate through the string until the null terminator is reached
while (*start != '\0') {
// Find the next occurrence of the newline character
end = strchr(start, '\n');
if (end != NULL) {
// Print the segment from 'start' to 'end' using precision width (%.*s)
// This safely prints the substring without requiring a temporary null-terminated buffer.
printf("Line %2d: %.*s\n", line_num++, (int)(end - start), start);
// Move the start pointer past the newline character for the next iteration
start = end + 1;
} else {
// Handle the final line (which may not end with a newline character)
printf("Line %2d: %s\n", line_num++, start);
break;
}
}
}
int main() {
// Best practice: Can use a string literal since the function doesn't modify it
const char *multiline_text = "Hello world!\nThis is line two.\nFinal line here.";
split_by_newline(multiline_text);
return 0;
}
/*
run:
Line 1: Hello world!
Line 2: This is line two.
Line 3: Final line here.
*/
