文件操作

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[]) {
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
   /* NSLog(@"the number is from 1 to 5");
	for (int i=1;	i<=5; i++) {
		NSLog(@"%d\n",i);
	}
	*/
	
	/*
	int number=6;
	for (int i=1; i<number; i++) {
		NSLog(@"%d\n",i);
	}
	 */
	
	/*
	const char *words[3]={"aaa","bb","sfsdfsdf"};
	int wordCount=3;
	for (int i=0; i<wordCount; i++) {
		NSLog(@"%s is %d characters long",words[i],strlen(words[i]));
	}
	 */
	
	
   /**
	
	//fopen()打开words.txt文件并读取文件内容，
	//tmp是nuix的临时目录，这计算机重启时会被清空
	FILE *wordFile=fopen("/tmp/word.txt", "r");
	char word[100];
	//fgets()从文件中读取一行并将其放入word，fgets（）会保留分开每一行的换行符，我们不需要，我们将换行符替换为0，这表示字符串的结束。
	while (fgets(word, 100, wordFile)) {
		word[strlen(word)-1]='\0';
		NSLog(@"%s is %d characters long",word,strlen(word));
	}
	//关闭文件
	fclose(wordFile);
	*/
	
	//main()的argc参数，此参数保存启动参数的数目。因为程序名称常用作启动参数传递，所以argc值常为1或者更大。argc[0]保存程序名称
	if(argc==1){
		NSLog(@"you need to provide a file name");
		return (1);
	}
	
	FILE *wordFile=fopen(argv[1], "r");
	char word[100];
	while (fgets(word, 100, wordFile)) {
		word[strlen(word)-1]='\0';
		NSLog(@"%s is %d characters long",word,strlen(word));
	}
	fclose(wordFile);
	
	
    [pool drain];
    return 0;
}