trim.cc

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

static inline void trim(char *&);

int main(int argc, char *argv[]) {
    char *s = "  foo bar    ";
    trim(s);
    printf("s = \"%s\"\n", s);
}

static inline void *trim(char *&s) {
    char *end;

    while (isspace((unsigned char) *s) || ispunct((unsigned char) *s)) s++;

    if (*s == 0)
        return s;

    end = s + strlen(s) - 1;
    while (end > s && isspace((unsigned char) *end) && ispunct((unsigned char) *s)) end--;

    end[1] = '\0';
}