Ç - 使用execvp用户输入
我目前想有我的C程序读取用户的Unix的参数。我到目前为止搜索这个网站,但我一直无法弄清楚到底是什么,我做错了 - 但无可否认我的指针执行技能是相当有限的。
I'm currently trying to have my C program read Unix arguments from the user. I've so far searched this site but I haven't been able to figure out exactly what I'm doing wrong - though admittedly my pointer implementation skills are rather limited.
下面是我怎么会有现在code;我一直在瞎搞与没有运气的指针。该错误也说,我需要使用常量*字符,但我已经在其他的例子看到的字符*可以由用户输入。
The following is how I have the code now; I've been messing around with the pointers with no luck. The errors are also saying that I need to use const *char, but I've seen in other examples the *char can be input by the user.
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
main()
{
char args[128];
//User input
printf("> ");
fgets(args, 128, stdin);
execvp(args[0], *args[0]);
}
我得到的错误是:
The error I get is as follows:
smallshellfile.c: In function ‘main’:
smallshellfile.c:13:21: error: invalid type argument of unary ‘*’ (have ‘int’)
smallshellfile.c:13:5: warning: passing argument 1 of ‘execvp’ makes pointer from integer without a cast [enabled by default]
/usr/include/unistd.h:575:12: note: expected ‘const char *’ but argument is of type ‘char’
有谁知道这个问题可能是什么?
Does anyone know what the problem may be?
您有几个问题:
-
* ARGS [0]
是没有意义的。ARGS
是数组。ARGS [0]
为char。是什么* ARGS [0]
?
*args[0]
is meaningless.args
is array.args[0]
is char. what is*args[0]
?
您必须创建的char *
的NULL结尾数组,传递为第一个参数。
You have to create a NULL-terminated array of char*
, to pass as 2nd argument.
ARGS [0]
是 ARGS的第一个字符
。你应该通过整个字符串(只是 ARGS
),不仅是它的第一个字符。
args[0]
is the first char in args
. you should pass the whole string (just args
), not only its first char.
尝试是这样的:
char *argv[]={args,NULL};
execvp(args,argv);