linux c语言拷贝u盘,用C语言编写linux cp 拷贝命令
(注：若转载本文请注明出处！)
对于初学者，学习文件操作参考作用，希望我的一些时间能给到大家一点帮助。
代码粗糙，但还是涉及到了很到指针移动操作，初学者可以参考，看代码，不多解释。
linux环境
假如有/home/hello.tar.gz
#gcc filecp.c -o filecp
#./filecp /home/hello.tar.gz
#cd /home/
#./filecp hello.tar.gz //上面两条命令 ，一样将会有一个文件拷贝文件产生在/home/hello_copy.tar.gz
#./filecp hello.tar.gz hello.gz //当前目录拷贝 和cp hello.tar.gz hello.gz 一样
#./filecp /home/hello.tar.gz .
#./filecp /home/hello.tar.gz ./ //两条命令一样，将会把hello.tar.gz 拷贝到当前目录
#./filecp /home/hello.tar.gz ./world
#./filecp /home/hello.tar.gz .world //两条命令一样，将会把hello.tar.gz拷贝到当前目录，但是名字变为world.tar.gz
#./filecp /home/hello.tar.gz ./world.gz
#./filecp /home/hello.tar.gz .world.gz //两条命令一样，将会把hello.tar.gz拷贝到当前目录，但是名字变为world.gz
注：不支持目录拷贝！
/*
*filecp.c
*/
#include
#include
#include
#include
#include
#include
void main(int argc, char **argv)
{
int fd_s, fd_d;
char buf[512];
char dstname[100];
int cnt = 0;
int i = 0, j = 0;
char *ptr = NULL;
int stepNum = 0;
//1. open source file.
fd_s = open(argv[1],O_RDONLY);
//2. open destination file.
if (argc <=1) {
printf("usage: ./filecp srcfilename dstfilename\n");
}
else if (argc <=2) {
while(argv[1][i] != '\0') {
dstname[i] = argv[1][i];
i++;
}
dstname[i] = '\0';
printf("dstname: %s\n",dstname);
ptr = strchr(dstname, '.');
if(ptr) {
printf("ptr %x - dstname %x = %d\n",ptr,dstname, ptr-dstname);
stepNum = i - (ptr - dstname) + 1;
printf("stepNUm: %d i : %d\n",stepNum,i);
int n = 0;
for (n=0; n<5; n++) {
for (j=0; j
i++;
}
printf(" last="" i:="" %d\n",i); printf("real destname: %s \n",dstname);
ptr[0] = '_';
ptr[1] = 'c';
ptr[2] = 'o';
ptr[3] = 'p';
ptr[4] = 'y';
printf("real destname: %s \n",dstname);
}
else {
printf("dstname ptr = NULL\n");
}
fd_d = open(dstname,O_RDWR|O_CREAT,0666);
}
else if (argc <=3) {
i = 0;
while(argv[1][i] != '\0') {
dstname[i] = argv[1][i];
i++;
}
dstname[i] = '\0';
if ((('.' == argv[2][0]) && ('\0' == argv[2][1]))|| \
(('.' == argv[2][0]) && ('/' == argv[2][1]) && \
('\0' == argv[2][2])) ){
ptr = strchr(dstname, '.');
char *tmp = NULL;
tmp = ptr;
while ('/' != tmp[0]) {
tmp--;
}
i = 0;
while('\0' != (++tmp)[0]) {
dstname[i] = tmp[0];
i++;
}
dstname[i] = '\0';
fd_d = open(dstname,O_RDWR|O_CREAT,0666);
}
else {
if (!strchr(++argv[2], '.')) {
i = 0;
j = 0;
--argv[2];
while ('\0' != argv[2][i]) {
if (('.' != argv[2][i]) && ('/' != argv[2][i])) {
dstname[j] = argv[2][i];
j++;
}
i ++;
}
dstname[j] = '\0';
ptr = strchr(++argv[1], '.');
while ('\0' != ptr[0]) {
dstname[j] = (ptr++)[0];
j++;
}
dstname[j] = '\0';
}
else {
i = 0;
j = 0;
while (('\0' != argv[2][i])) {
if('/' != argv[2][i]) {
dstname[j] = argv[2][i];
j++;
}
i++;
}
dstname[j] = '\0';
}
fd_d = open(dstname,O_RDWR|O_CREAT,0666);
}
}
//3. read source file data.
while((cnt = read(fd_s, buf, 512)) > 0 ) {
/*4. write data to target file.*/
// printf("cnt : %d\n",cnt);
write(fd_d, buf, cnt);
}
//5. close file descriptor.
close(fd_s);
close(fd_d);
}
阅读(525) | 评论(0) | 转发(0) |