Strings

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

int main(void) {
    char name[32] = "Ada";
    strcat(name, " Lovelace");
    printf("%s has %zu characters\n", name, strlen(name));
    printf("%d %d\n", strcmp("abc", "abc") == 0, strncmp(name, "Ada", 3) == 0);

    char upper[32];
    for (size_t i = 0; i <= strlen(name); i++) upper[i] = (char) toupper((unsigned char) name[i]);
    printf("%s\n", upper);

    char line[] = "a,b,c";
    for (char *part = strtok(line, ","); part; part = strtok(NULL, ",")) printf("[%s]", part);
    printf("\n");

    char buf[16];
    snprintf(buf, sizeof buf, "%03d|%.2f", 7, 3.14159);
    puts(buf);

    regex_t re;
    regmatch_t m[2];
    const char *text = "order 7 pending";
    regcomp(&re, "order ([0-9]+)", REG_EXTENDED);
    if (regexec(&re, text, 2, m, 0) == 0) printf("%.*s\n", (int) (m[1].rm_eo - m[1].rm_so), text + m[1].rm_so);
    regfree(&re);
    return 0;
}