文件IO-getcwd-chdir-fchdir-chroot

chdir

getcwd

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#define MAX 512

int main(int argc, char * argv[])
{
    // 方法一
    char path[MAX];
    path[0] = '\0';
    getcwd(path, sizeof(path));
    puts(path);

    // 改变路径
    if (chdir("/home") < 0)
    {
        perror("Error chdir.\n");
        exit(EXIT_FAILURE);
    }

    // 方法二
    char * buf = NULL;
    buf = getcwd(NULL, 0);
    puts(buf);
    free(buf);

    exit(EXIT_SUCCESS);
}

第二版

/*
	API chdir \ getcwd
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#define MAX 20


int main(int argc, char *argv[])
{
	// getcwd,获取当前路径
	char *path = NULL;
	path = getcwd(NULL, 0);
	getcwd(NULL, 0);
	puts("Original path is :");
	puts(path);
	
	// 切换路径地址
	if (chdir("../") < 0)
	{
		perror("Error chdir:");
		exit(EXIT_FAILURE);
	}
	
	path = getcwd(NULL, 0);
	puts("Now path is:");
	puts(path);
	   
	free(path);
	exit(EXIT_SUCCESS);
}

第三版

/*
	API chdir \ getcwd
	切换目录地址
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>


int main(int argc, char *argv[])
{
	// getcwd,获取当前路径
	char *path = NULL;
	path = getcwd(NULL, 0);
	getcwd(NULL, 0);
	puts("Original path is :");
	puts(path);
	
	// 读取参数，目标路径
	char * o_path = NULL;
	o_path = argv[1];
	puts("I want to munu:");
	puts(o_path);
	
	// 切换路径地址
	if (chdir(o_path) < 0)
	{
		perror("Error chdir:");
		exit(EXIT_FAILURE);
	}
	
	path = getcwd(NULL, 0);
	puts("Now path is:");
	puts(path);
	   
	free(path);
	exit(EXIT_SUCCESS);
}

第四版

/*
	API chdir \ getcwd
	切换目录地址
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>

int main(int argc, char *argv[])
{
	char o_path[20];
	// getcwd,获取当前路径
	char *path = NULL;
	path = getcwd(NULL, 0);
	getcwd(NULL, 0);
	puts("Original path is :");
	puts(path);
	
	for(;;)
	{
		puts("I want to munu:");
		scanf("%s", o_path);
		puts(o_path);
		
		if (strcmp(o_path, "q") == 0)
		{
			puts("quit");
			break;
		}
		// 切换路径地址
		if (chdir(o_path) < 0)
		{
			perror("Error chdir:");
			exit(EXIT_FAILURE);
		}
		
		path = getcwd(NULL, 0);
		puts("Now path is:");
		puts(path);
		
	}
	   
	free(path);
	exit(EXIT_SUCCESS);
}

  

makefile

cshell:code.o
	gcc -o cshell code.o
code.o:code.c
	gcc -c code.c
.PHONY: clean
clean:
	rm -f *.o
	rm -f cshell