c - 如何在 C 中找到 Unix system() 函数路径

Question

我正在做一个关于 shell 的项目，我想要给我 system() 函数使用的路径的代码。

例如，当我输入命令时

输入目录

回复会是

dir 是外部命令(/bin/dir)

这是我达到的，但它不起作用

else if(strcmp(arg3[0],"type")==0) //if type command
        {
            if(strcmp(arg3[1],"cat")==0 || strcmp(arg3[1],"rm")==0 || strcmp(arg3[1],"rmdir")==0 || strcmp(arg3[1],"ls")==0 || strcmp(arg3[1],"cp")==0 ||                   strcmp(arg3[1],"mv")==0 || strcmp(arg3[1],"exit")==0 || strcmp(arg3[1],"sleep")==0 || strcmp(arg3[1],"type")==0|| strcmp(arg3[1],"history") ==0)
            {
                printf("%s is a Rshell builtin\n", arg3[1]);
            }
            else
            {
                printf("%s is an external command\n", arg3[1]); 
                char * pPath;
                pPath = getenv ("PATH");
                 if (pPath!=NULL)
                    printf ("The current path is: %s",pPath);


            }
        }

Answer 1

听起来您正在寻找 which 命令:

$ which ls
/bin/ls