1. 用fgets和fputs实现文件的拷贝
#include <stdio.h>
int main(int argc, const char *argv[])
{
FILE *fr=fopen(argv[1],"r");
FILE *fw=fopen("cpy.txt","w");
char buf[256];
while(fgets(buf,256,fr)){
fputs(buf,fw);
}
return 0;
}

2. 用fgets实现计算一个文件有几行。
#include <stdio.h>
int main(int argc, const char *argv[])
{
int count=0;
FILE *fp=fopen(argv[1],"r");
char buf[100];
while(fgets(buf,100,fp)){
count++;
}
printf("%s有%d行\n",argv[1],count);
return 0;
}
3.用fgetc实现,计算一个文件有几行,要求封装成函数,用命令行传参,
#include <stdio.h>
int linecount(const char *filename){
FILE *fp = fopen(filename,"r");
int count=0;
char a;
while((a=fgetc(fp))>0){
if(a=='\n'){
count++;
}
}
return count;
}
int main(int argc, const char *argv[])
{
printf("%d\n",linecount(argv[1]));
return 0;
}