Journal Portage de TapTempo en C à la Unix-like

Salut Nal,

Il manquait une version C à la tradition Unix, c'est maintenant fait !

Du coup, pour préserver l'esprit, options courtes uniquement et pas de version, mais pour le reste, c'est assez complet avec contrôle des bornes pour les paramètres. Il ne manque que la page de manuel, ce sera pour une autre fois :)

#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/time.h>
#include <unistd.h>

#define NSAMPLES 5
#define MAX_NSAMPLES 20
#define RESET_TIME 5
#define PRECISION 0

extern  char *__progname;

static  void usage(void);

int
main(int argc, char *argv[])
{
        double           times[MAX_NSAMPLES];    
        int              curlen = 0;
        double           curtime;
        struct timeval   tp;
        int              ch;
        char            *p = NULL, *r = NULL, *s = NULL;
        int              precision = PRECISION, reset_time = RESET_TIME, nsamples = NSAMPLES;
        char             fmtstr[30];
        char            *line = NULL;
        size_t           linesize = 0;
        ssize_t          linelen;

        while ((ch = getopt(argc, argv, "p:r:s:")) != -1)
                switch (ch) {
                case 'p':
                        p = optarg;     
                        break;
                case 'r':
                        r = optarg;             
                        break;
                case 's':
                        s = optarg;             
                        break;
                default:
                        usage();
                }
        argc -= optind;
        if (argc > 0)
                warnx("too many arguments");
        if (p && sscanf(p, "%i", &precision) != 1)
                warnx("-p argument: not an integer");
        if (r && sscanf(r, "%i", &reset_time) != 1)
                warnx("-r argument: not an integer");
        if (s && sscanf(s, "%i", &nsamples) != 1)
                warnx("-r argument: not an integer");
        if (precision < 0 || precision > 6) {
                warnx("-p argument: should be an integer between 0 and 6");
                precision = PRECISION;
        }
        if (reset_time < 1) {
                warnx("-r argument: should be at least 1");
                reset_time = RESET_TIME;
        }
        if (nsamples < 2 || nsamples > MAX_NSAMPLES) {
                fprintf(stderr, "%s: -s argument: should be an integer between 2 and %d\n",
                    __progname, MAX_NSAMPLES);
                nsamples = NSAMPLES;
        }
        int ret = snprintf(fmtstr, sizeof(fmtstr), "Tempo: %%.%df bpm ", precision);
        if (ret == -1 || ret >= sizeof(fmtstr))
                errx(1, "snprintf");

        printf("Hit enter key for each beat (q to quit).");
        while ((fflush(stdout), linelen = getline(&line, &linesize, stdin)) != -1) {
                if (!strncmp(line, "q\n", linelen))
                        break;
                gettimeofday(&tp, NULL);
                curtime = tp.tv_sec + tp.tv_usec / 1e6;
                if (curlen > 0 && curtime - times[curlen-1] > reset_time)
                        curlen = 0;
                if (curlen == nsamples)
                        for (int i = 0; i < nsamples - 1; i++)
                                times[i] = times[i+1];
                else
                        curlen++;
                times[curlen-1] = curtime;
                if (curlen < 2) {
                        printf("[Hit enter key one more time to start bpm computation...]");
                        continue;
                }
                printf(fmtstr, 60 * (curlen-1) / (curtime - times[0]));
        }
        free(line);

        if (ferror(stdin))
                warn("getline");
        puts("Bye Bye!");

        return (0);
}

static void
usage(void)
{
        fprintf(stderr, "usage: %s [-p precision] [-r reset-time] [-s samples]\n", __progname);
        exit(1);
}

J'ai pas vraiment l'habitude du C, donc c'était l'occasion de s'amuser un peu et essayer d'écrire un programme C sans segfaults :)