Question

I would like to capture special characters such as \n from the command line into a C program.

For example, for the following program, if I run ./a.out “\nfoo\n” , I’d like to to print (newline) foo (newline) instead of “\nfoo\n”. How can I capture that in to a string?

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

int main(int argc, char ** argv){
    if(argc >1){
        char * s = strdup(argv[1]);
        printf("%s\n", s);
        free(s);
    }
    return 0;
}

Edit: sorry, by (newline) foo (newline), I mean the acutal output is

foo

Currently,the output is literally “\nabc\n”.(newlines are not printed because s captures “\n” 2 characters instead of the ‘\n’ character). Sorry about the confusion.

Answer 1

make a new string, iterate through the old string adding characters to the new string. if you ever see the '\' character, add a special character to the new string based on the next character in the old string.