initial parser

[calc.git] / calc.c

/* depend: */
/* cflags: */
/* linker: atoi.o fdprintf.o parser.o */

//#include <malloc.h>
#include <stddef.h>
#include <stdio.h>
#include <unistd.h>

#include "atoi.h"
#include "debug.h"
#include "fdprintf.h"
#include "parser.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))

/* gobal variables */

char *progname = NULL;
int verbose = 2;

/* help function */

int usage (int ret)
{
    int fd = ret ? stdfderr : stdfdout;
    fdprintf (fd, "usage: %s\n", progname);
    fdprintf (fd, " -h : help message\n");
    fdprintf (fd, " -v : verbose level (%d)\n", verbose);

    return ret;
}

/* main function */

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

    /* program name */

    progname = argv[0];
    while (progname[i] != '\0') {
        if ((progname[i] == '/') || (progname[i] == '\\')) {
            progname += i + 1;
            i = 0;
        } else {
            i++;
        }
    }

    /* argument processing */

     while (argc-- > 1) {
        char *arg = *(++argv);
        if (arg[0] != '-') {
            PRINTERR ("%s: invalid option -- %s\n", progname, arg);
            return usage (1);
        }
        char c = arg[1];
        switch (c) {
        case 'v':
            arg = (arg[2]) ? arg + 2 : (--argc > 0) ? *(++argv) : NULL;
            if (arg == NULL) {
                PRINTERR ("%s: missing verbose level\n", progname);
                return usage (1);
            }
            verbose = atoi (arg);
            break;
        case 'h':
        default:
            return usage (c != 'h');
        }
    }

    /* read from input stream */

    while ((n = read (stdfdin, pt, BUFFER_SIZE - (pt - buffer))) != 0) {
        VERBOSE (DEBUG, PRINTOUT ("read %d bytes\n", n));
        n += (pt - buffer);
        if ((n == 2) && (buffer[0] == '.')) {
            return 0;
        }

        /* look for end of line */
        for (i = 0, j = 0; i < n; i++) {
            if (buffer[i] == '\n') {
                buffer[i] = 0;
                VERBOSE (DEBUG, PRINTOUT ("line(%d): %s\n", j, buffer + j));
                element_t *element = parser (buffer);
                if (element == (void *)(-1)) {
                    VERBOSE (WARNING, PRINTOUT ("error while parsing: %s\n", buffer));
		} else {
                    print_element (element, 0);
                }
                //fsync (stdfdout);
                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;
            }
        }
    }

    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: */