clean ascii

[ascii.git] / calc.c

/* depend: */
/* cflags: */
/* linker: */

#include <assert.h>
#include <getopt.h>
#include <malloc.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

/* constants */

//#define BUFFER_SIZE 4096
#define BUFFER_SIZE 256

/* macros */

#define CEIL(x, y) (((x) + (y) - 1) / (y))
#define MIN(x, y) (((x) < (y)) ? (x) : (y))
#define MAX(x, y) (((x) > (y)) ? (x) : (y))

/* verbose */

#define ERROR 0
#define WARNING 1
#define INFO 2
#define DEBUG 3

#define VERBOSE(level, statement...) do { if (level <= verbose) { statement; } } while(0)

/* gobal variables */

char *progname = NULL;
int verbose = 0;

/* help function */

void usage (int ret)
{
    FILE *fd = ret ? stderr : stdout;
    fprintf (fd, "usage: %s\n", progname);
    fprintf (fd, " -h : help message\n");
    fprintf (fd, " -v : verbose level (%d)\n", verbose);

    exit (ret);
}

/* main function */

int main (int argc, char *argv[]) 
{
    char buffer[BUFFER_SIZE + 1] = {0};
    char *pt = buffer;
    int i, j = 0, n;

    progname = argv[0];

    int c;
    while ((c = getopt(argc, argv, "hv:")) != EOF) {
        switch (c) {
        case 'v':
            verbose = atoi (optarg);
            break;
        case 'h':
            VERBOSE (INFO, usage (0));
            break;
        default:
            VERBOSE (ERROR, usage (1));
        }
    }
    if (argc - optind != 0) {
        VERBOSE (ERROR, fprintf (stderr, "%s: invalid option -- %s\n", progname, argv[optind]));
        VERBOSE (ERROR, usage (1));
    }

    /* read from input stream */
    while ((n = read (STDIN_FILENO, pt, BUFFER_SIZE - (pt - buffer))) != 0) {
        VERBOSE (DEBUG, fprintf (stdout, "read %d bytes\n", n));
        n += (pt - buffer);

        /* look for end of line */
        for (i = 0, j = 0; i < n; i++) {
            if (buffer[i] == '\n') {
                buffer[i] = 0;
                VERBOSE (DEBUG, fprintf (stdout, "line(%d): %s\n", j, buffer + j));
                j = i + 1;
            }
        }

        /* keep remainding */
        if (j < n) {
            for (i = 0; i < n - j; i++) {
                buffer[i] = buffer[i + j];
            }
            pt = buffer + n - j;
            for (i = n - j; i < BUFFER_SIZE; i++) {
                buffer[i] = 0;
            }
        }
    }

    /* check that nothing is left behind */

    VERBOSE (DEBUG, fprintf (stdout, "last\n"));
    VERBOSE (DEBUG, fprintf (stdout, "line(%d): %s\n", j, buffer + j));

    return 0;
}

// test: calc.exe -h
// test: calc.exe -h | awk '/usage:/ { rc=1 } END { exit (1-rc) }'
// test: calc.exe -_ 2> /dev/null | awk 'END { if (NR == 0) { exit(0) } else exit (1) }'
// test: calc.exe -_ 2>&1 | awk '/usage:/ { rc=1 } END { exit (1-rc) }'
// test: echo "foo\nbar\nfoobar" | calc.exe -v3

/* vim: set ts=4 sw=4 et: */