自己實現了cat這個命令

#include<stdio.h>
#include<unistd.h>
#define MAX 1000
void filecopy(FILE* fin,FILE* fout);


int main(int argc,char **argv)
{
    FILE  *f = NULL;
    char buffer[MAX];
    int i = 1;
    int str_size = 0;
    printf("%d\n",argc);
    if(argc == 1)
    {
	filecopy(stdin,stdout);
    }
    else
    {
	for(i = 1;i < argc;i++)
	{
	    if(getcwd(buffer,MAX) == NULL)
	    {
		printf("wrong answer!!");
	    }
	    else
	    {
		str_size = strlen(buffer);
		buffer[str_size] = '\\';
		buffer[str_size + 1] = '\0';
		strcat(buffer,argv[i]);
	    }
	    printf("%s\n",buffer);
	    if((f = fopen(buffer,"r")) == NULL)
	    {
		printf("cat:can't open %s\n",argv[i]);
		return 1;
	    }
	    else
	    {
		filecopy(f,stdout);
		fclose(f);
	    }
	}
    }
    return 0;
}

void filecopy(FILE*fin,FILE*fout)
{
    int c = 0;

    while((c = getc(fin)) != EOF)
    {
	putc(c,fout);
    }
}

主要是對C語言對文件的一些操作。對他們的讀寫操作