自己实现more命令

#include    <stdio.h>
#include    <stdlib.h>

#define PAGELEN 24
#define LINELEN 512

int see_more(FILE*);
void do_more(FILE*);

int main(int ac, char* av[])
{
    FILE *fp;
    if(ac==1)
        do_more(stdin);
    //    printf("%s","Please input file name.
");
    else
    {    
        while(--ac)
        if((fp=fopen(*++av,"r"))!=NULL)
        {
            do_more(fp);
            fclose(fp);    
        }
    }
    
            
}

void do_more(FILE* fp)
{
    int num_of_lines=0;
    char line[LINELEN];
    int reply;
//    int see_more();
    FILE* fp_tty;
    fp_tty=fopen("/dev/tty","r");
    if(fp_tty==NULL) exit(1);
    while(fgets(line,LINELEN,fp))
    {
        if(num_of_lines==PAGELEN)
        {
            reply=see_more(fp_tty);
            if(reply==0)
                break;
            num_of_lines-=reply;
        }
        if(fputs(line,stdout)==EOF)
            exit(1);
        num_of_lines++;    
    }

}

int see_more(FILE* cmd)
{
    int c;
    //printf("33[7m more? 33[m");
    printf("33[32;49;1m [more?] 33[39;49;0m");
    //033[32;49;1m [MORE?] 33[39;49;0m
    while((c=getc(cmd))!=EOF)
    {
        if(c=='q')
            return 0;
        
        if(c=='
')
            return 1;
        
        if(c==' ')
            return PAGELEN;
    }
}