dba.c

perl 解释器

/*
 * dba	dbm analysis/recovery
 */

#include <stdio.h>
#include <sys/file.h>
#include "EXTERN.h"
#include "sdbm.h"

char *progname;
extern void oops();

int
main(argc, argv)
char **argv;
{
	int n;
	char *p;
	char *name;
	int pagf;

	progname = argv[0];

	if (p = argv[1]) {
		name = (char *) malloc((n = strlen(p)) + 5);
		strcpy(name, p);
		strcpy(name + n, ".pag");

		if ((pagf = open(name, O_RDONLY)) < 0)
			oops("cannot open %s.", name);

		sdump(pagf);
	}
	else
		oops("usage: %s dbname", progname);

	return 0;
}

sdump(pagf)
int pagf;
{
	register b;
	register n = 0;
	register t = 0;
	register o = 0;
	register e;
	char pag[PBLKSIZ];

	while ((b = read(pagf, pag, PBLKSIZ)) > 0) {
		printf("#%d: ", n);
		if (!okpage(pag))
			printf("bad\n");
		else {
			printf("ok. ");
			if (!(e = pagestat(pag)))
			    o++;
			else
			    t += e;
		}
		n++;
	}

	if (b == 0)
		printf("%d pages (%d holes):  %d entries\n", n, o, t);
	else
		oops("read failed: block %d", n);
}

pagestat(pag)
char *pag;
{
	register n;
	register free;
	register short *ino = (short *) pag;

	if (!(n = ino[0]))
		printf("no entries.\n");
	else {
		free = ino[n] - (n + 1) * sizeof(short);
		printf("%3d entries %2d%% used free %d.\n",
		       n / 2, ((PBLKSIZ - free) * 100) / PBLKSIZ, free);
	}
	return n / 2;
}