小编ile*_*nt2的帖子

我是系统调用和C编程的新手,正在完成我的大学任务.

我想调用'ls'命令并让它打印目录.

我有什么:(我添加了评论,这样你就可以看到我看到的每个变量.

int execute( command* cmd ){

  char full_path[50];
  find_fullP(full_path, p_cmd); 
  //find_fullP successfully updates full_path to /bin/ls
  char* args[p_cmd->argc];
  args[0] = p_cmd->name;
  int i;
  for(i = 1; i < p_cmd->argc; i++){
      args[i] = p_cmd->argv[i];
  }

/*
 * this piece of code updates an args variable which holds arguments 
 * (stored in the struct) in case the command is something else that takes 
 * arguments. In this case, it will hold nothing since the command 
 * will be just 'ls'. …

在下面的代码中,如果字符是大写字母,则打印第一个语句,但是对于小写字母,打印第二个语句.这是什么原因？我正在使用dev c ++编译我的代码.

#include<stdio.h>
#include<conio.h>
#include<ctype.h>

int main()
{
    char c;
    printf("enter a character\n");
    scanf("%c",&c);

    int i;
    i=isalpha(c);
    if(i==1)
        printf("entered character is an alphabet\n");
    else
        printf("entered character is not an alphabet\n");

    getch();
    return 0;
}