自己動手寫shell命令之more

標籤：linux   shell   

unix下more命令的簡單實現：

#include <stdio.h>#define PAGELEN 24#define LINELEN 512int do_more(FILE * file);int see_more(FILE * file);int main(int argc,char * argv[]){FILE * fp;if(argc == 1)do_more(stdin);else{int argv_index = 1;while(argc > 1){if((fp = fopen(argv[argv_index],"r")) == NULL)exit(1);do_more(fp);fclose(fp);argv_index++;argc--;}}return 0;}int do_more(FILE * fp){char buffer[LINELEN];int number_of_lines = 0;int reply;FILE * ftty;ftty = fopen("/dev/tty","r");if(ftty == NULL)exit(1);while(fgets(buffer,LINELEN,fp)){if(number_of_lines == PAGELEN){fputs(buffer,stdout);reply = see_more(ftty);if(reply == 0)break;if(reply == 1)number_of_lines = 0;//if(reply == 2)//number_of_lines--;}else{number_of_lines++;fputs(buffer,stdout);}}}int see_more(FILE * fp){char c;printf("enter your command(q space or enter):");while((c = getc(stdin)) != EOF){if(c == 'q')//按q退出return 0;if(c == ' ')return 1;//按空格顯示下一頁if(c == 'n')return 2;//按n顯示下一行}return 3;}

自己動手寫shell命令之more