linux命令: tree的c实现

#include<stdio.h>
#include<dirent.h>
#include<sys/stat.h>
#include<sys/types.h>
#include<string.h>

#define MAXNAME 200
void s_printf(char *filename,int depth);
void s_dirwalk(char *dirname,int depth,void (*fcn)(char *,int));
void listdirtree(char *dirname,int depth);

int main(int argc,char **argv)
{
if(argc == 1)
listdirtree(".",0);
else
{
printf("%s\n",argv[1]);
listdirtree(*++argv,0);
}
return 0;
}

void listdirtree(char *dirname,int depth)
{
struct stat stbuf;
if((stat(dirname,&stbuf)) == -1)
{
fprintf(stderr,"listdirtree:can't read file %s information!\n",dirname);
return;
}
if((stbuf.st_mode & S_IFMT) == S_IFDIR)
s_dirwalk(dirname,depth,listdirtree);
}

void s_dirwalk(char *dirname,int depth,void (*fcn)(char *,int))
{
char name[MAXNAME];
struct dirent *fip;
DIR *dp;
if((dp = opendir(dirname)) == NULL)
{
fprintf(stderr,"s_dirwalk:can't open %s\n",dirname);
return;
}
while((fip = readdir(dp)) != NULL)
{
if(strcmp(fip->d_name,".") == 0 || strcmp(fip->d_name,"..") == 0)/*skip directory '.' and '..'*/
continue;
if(strlen(dirname) + strlen(fip->d_name) + 2 > sizeof(name))
{
fprintf(stderr,"s_dirwalk:%s/%s is too long!\n",dirname,fip->d_name);
return;
}
else
{
s_printf(fip->d_name,depth);
sprintf(name,"%s/%s",dirname,fip->d_name);
(*fcn)(name,depth + 1);
}
}
closedir(dp);
}

void s_printf(char *filename,int depth)
{
while(depth-- > 0)
printf("|  ");
printf("|--");
printf("%s\n",filename);
}