/* gbos libc C helpers (compiled once, linked into every program). */
#include "gbos.h"

/* print an unsigned int in decimal */
void putu(unsigned int n) {
    char buf[5];
    unsigned char i = 0;
    if (n == 0) { putc('0'); return; }
    while (n) { buf[i++] = '0' + (n % 10); n = n / 10; }
    while (i) putc(buf[--i]);
}

/* parse a decimal number (stops at the first non-digit) */
unsigned char atou(const char *s) {
    unsigned char n = 0;
    while (*s >= '0' && *s <= '9') { n = n * 10 + (*s - '0'); s++; }
    return n;
}

/* tokenize the argument string in place into argv[]; returns argc.
   (replaces the spaces in the arg string with NULs) */
unsigned char argv_parse(char **argv, unsigned char maxv) {
    char *p = getargs();
    unsigned char argc = 0;
    for (;;) {
        while (*p == ' ') p++;
        if (*p == 0) break;
        if (argc < maxv) argv[argc] = p;
        argc++;
        while (*p != 0 && *p != ' ') p++;
        if (*p == ' ') *p++ = 0;
    }
    return argc;
}

/* return nonzero if single-char flag `f` appears (as -f or within -abc) */
unsigned char hasflag(char **argv, unsigned char argc, char f) {
    unsigned char i, j;
    for (i = 0; i < argc; i++) {
        if (argv[i][0] != '-') continue;
        for (j = 1; argv[i][j]; j++)
            if (argv[i][j] == f) return 1;
    }
    return 0;
}

/* return the value for option -<opt> ("-n 5" or "-n5"), or 0 if absent */
char *optval(char **argv, unsigned char argc, char opt) {
    unsigned char i;
    for (i = 0; i < argc; i++) {
        if (argv[i][0] == '-' && argv[i][1] == opt) {
            if (argv[i][2]) return &argv[i][2];
            if (i + 1 < argc) return argv[i+1];
            return 0;
        }
    }
    return 0;
}