dir.c

本程序通过系统调用stat读出文件大小属性

#include <stdio.h>
#include <string.h>
#include <fcntl.h>		/* flags for read & write */
#include <sys/types.h>		/* typedefs */
#include <sys/stat.h>		/* structure returned by stat */
#include <dirent.h>
//#inlcude "syscalls.h"

#define MAX_PATH		1024

void fsize(char *);
void dirwalk(char *dir, void (*fcn)(char*));

/* print file sizes */
int
main(int argc, char **argv)
{
	if (argc == 1)		/*default: current directory */
		fsize(".");
	else
		while (--argc > 0)
			fsize(* ++argv);
	return 0;
}

/* fsize: print size of file "name" */
void
fsize(char *name)
{
	struct stat stbuf;
	
	if (stat(name, &stbuf) == -1) {
		fprintf(stderr, "fsize: cant access %s\n", name);
		return;
	}
	//printf("fsize: %s \n", name);
	if ( (stbuf.st_mode & S_IFMT) == S_IFDIR) {
		
		dirwalk(name, fsize);
	}
	printf("%8ld %s\n", stbuf.st_size, name);
}

/* dirwalk: apply fcn to all files in dir */
void
dirwalk(char *dir, void (*fcn)(char *))
{
	char	name[MAX_PATH];
	DIR	*dfd;
	struct dirent	*dp;
	
	///printf("dirwalk: %s \n", dir);
	if ( (dfd=opendir(dir)) == NULL) {
		fprintf(stderr, "dirwalk: cant open %s\n", dir);
		return;
	}
	while ( (dp=readdir(dfd)) != NULL) {
		if (strcmp(dp->d_name, ".") == 0
			|| strcmp(dp->d_name, "..") == 0)
			continue;	/* skip self and parent */
		if (strlen(dir)+strlen(dp->d_name)+2 > sizeof(name))
			fprintf(stderr, "dirwalk: name %s/%s too long\n", dir, dp->d_name);
		else {
			sprintf(name, "%s/%s", dir, dp->d_name);
			(*fcn)(name);
		}
	}
	closedir(dfd);
}