#import<Foundation/Foundation.h>
int main(int argc, char *argv[])
{
if (argc == 1)
{
NSLog(@"you need to provide a file name");
return 1;
}
FILE* file = fopen(argv[1], "r");
char words[100];
while (fgets(words, 100, file))
{
words[strlen(words) - 1] = '\0';
NSLog(@"%s is %d character long", words, strlen(words));
}
fclose(file);
return 0;
}
argc是参数个数,argv是参数值:
例如上述程序在终端下运行时输入:
./main.exe words.txt
若argc==1表示只输入了./main.exe,缺乏文件名。
argv[0]中存程序名字(./main.exe);
argv[1]中存文件名(words.txt).