<The c programming language>Exercise-23答案求解释。

Question

本人新手，下面是rick的答案，不明白的是 if( line[t] == ' " ')
in_quote = 1;
if( ! in_quote )
{ }
else
{}
作者是怎样确保下面的if在双引号' “ '内还是在双引号外的，求大神帮助。原代码在下面。
#include

#define MAXLINE 1000 /* max input line size /
char line[MAXLINE]; /*current input line/

int getline(void); /* taken from the KnR book. */

int
main()
{
int in_comment,len;
int in_quote;
int t;

in_comment = in_quote = t = 0;
while ((len = getline()) > 0 )
{
t=0;
while(t < len)
{
if( line[t] == '"')
in_quote = 1;

  if( ! in_quote )
  {
        if( line[t] == '/' && line[t+1] == '*')
            {
                t=t+2;
                in_comment = 1;
            }
        if( line[t] == '*' && line[t+1] == '/')
            {
                t=t+2;
                in_comment = 0;
            }
        if(in_comment == 1)
         {
                t++;
            }
        else
            {
                printf ("%c", line[t]);
                t++;
            }
  } 
  else
  {
          printf ("%c", line[t]);
          t++;
  }
    }
}

return 0;
}

/* getline: specialized version */
int getline(void)
{
int c, i;
extern char line[];

for ( i=0;i<MAXLINE-1 && ( c=getchar()) != EOF && c != '\n'; ++i)
line[i] = c;
if(c == '\n')
{
line[i] = c;
++i;
}
line[i] = '\0';
return i;

}

Answer 1

意思是判断是否为字符为双引号