How to remove \n or \t from a given string in C?

Question

How can I strip a string with all \\n and \\t in C?

Answer 1

I like to make the standard library do as much of the work as possible, so I would use something similar to Evan's solution but with strspn() and strcspn().

#include 
#include 
#include 

#define SPACE " \t\r\n"

static void strip(char *s);
static char *strip_copy(char const *s);

int main(int ac, char **av)
{
    char s[] = "this\t is\n a\t test\n test";
    char *s1 = strip_copy(s);
    strip(s);
    printf("%s\n%s\n", s, s1);
    return 0;
}

static void strip(char *s)
{
    char *p = s;
    int n;
    while (*s)
    {
        n = strcspn(s, SPACE);
        strncpy(p, s, n);
        p += n;
        s += n + strspn(s+n, SPACE);
    }
    *p = 0;
}

static char *strip_copy(char const *s)
{
    char *buf = malloc(1 + strlen(s));
    if (buf)
    {
        char *p = buf;
        char const *q;
        int n;
        for (q = s; *q; q += n + strspn(q+n, SPACE))
        {
            n = strcspn(q, SPACE);
            strncpy(p, q, n);
            p += n;
        }
        *p++ = '\0';
        buf = realloc(buf, p - buf);
    }
    return buf;
}