一個objective-c程式及main函數之參數

#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是參數個數，argv是參數值：

例如上述程式在終端下運行時輸入：

./main.exe words.txt

 

若argc==1表示只輸入了./main.exe，缺乏檔案名稱。

argv[0]中存程式名字(./main.exe);

argv[1]中存檔案名稱(words.txt).