cat.c

来自「This is to bulid a sample linux shell.」· C语言 代码 · 共 46 行

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

int main(int argc, char *argv[])
{
 	FILE *fp;
	char ch;
	if(argc < 2 || argc > 3)
	{
		printf("daemon: Insufficient or Extra Arguments.\n");
		exit(0);
	}
	if(!strcmp(argv[1],"<"))
	{
		if(argc==2)
		{
			printf("daemon: Insufficient Arguments\n");
			return 0;
		}
		fp = fopen(argv[2],"w");
		ch = getchar();
		while(ch != '~')
		{
			putc(ch,fp);
			ch = getchar();
		}
		fclose(fp);
		return 0;		
	}
	fp=fopen(argv[1],"r");
	if(fp == NULL)
	{
		printf("daemon: %s file not found.\n",argv[1]);
		exit(0);
	}
	ch=getc(fp);
	while(ch!=EOF)
	{
		printf("%c",ch);
		ch=getc(fp);
	}
	fclose(fp);
	return 0;
}