p9-2.c

SUN Solaris8平台下进程间通信

#include <stdio.h>
char *menu[]={    /*命令菜单*/
    "a - add new record",
    "d - delete record",
    "q - quit",
    NULL
};
int getchoice(char *greet,char *choices[]);
FILE *input,*output;
int main(void)
{
    int choice = 0;
    input = fopen("/dev/tty","r");
    output = fopen("/dev/tty","w");
    if(!input||!output) {
        fprintf(stderr, "unable to open /dev/tty\n");
    exit(1);
}
    do {
        choice = getchoice("Please select a action", menu);
        printf ("You have chosen: %c\n", choice);
    } while (choice != 'q') ;
    exit (0);
}
int getchoice(char *greet, char *choices[])
{
    int chosen = 0;
    int selected;
    char **option;
    do {
        fprintf(output, "Choice: %s\n", greet);
        option = choices;
        /*打印选择菜单*/
        while(*option) {
            fprintf (output,"%s\n", *option);
            option++;
        }
        /*读入命令字符,抛弃该行其它字符 */
        selected = fgetc(input);
        while (fgetc(input)!= '\n' );
        /* 检查命令字符，正确置chosen=1*/
        option = choices;
        while(*option){
            if(selected == *option[0]) {
                chosen = 1 ;
                break;
            }
            option++;
        }
        /*命令不正确，提示重新输入命令*/
        if(!chosen)
            fprintf(output,"Incorrect choice,select agian\n");
    } while(!chosen);  /*直至得到正确的命令*/
    return selected;
}