用C语言编写一个Linux下的简单shell程序

用C语言编写一个Linux下的简单shell程序

这是一个简单的C程序，展示了如何进行系统调用执行logout cd ls pwd pid rm mkdir mv cp等命令，这是一个简单的命令解释程序shell，其源代码如下：

#include >stdio.h< #include >string.h< #include >unistd.h< #include >stdlib.h< #include >sys/types.h< #include >errno.h< #include >sys/stat.h< char parsecmd(char *); /************关于本文档******************************************** *filename:用C语言编写一个Linux下的简单shell程序 *purpose:展示了C语言如何进行系统调用执行logout cd ls pwd pid rm mkdir mv cp等命令 *wrote by: zhoulifa([email protected]) 周立发(http://zhoulifa.bokee.com) Linux爱好者 Linux知识传播者 SOHO族 开发者 最擅长C语言编程 *date time:2006-07-16 15:00:00 *Note: 任何人可以任意复制代码并运用这些文档，当然包括你的商业用途 * 但请遵循GPL。 *Hope:希望越来越多的人贡献自己的力量，为科学技术发展出力 *********************************************************************/ int main(int argc, char ** argv) { char cmd[1024]; char tmp[101]; char b = 'F'; char * p; while(1) { memset(cmd, 0, 1024); printf("Next command%% ");/*显示提示信息*/ fgets(cmd, 1000, stdin);/*接受用户输入，命令最长1000个字符*/ cmd[strlen(cmd) - 1] = 0;/*去掉输入的回车符*/ b = parsecmd(cmd);/*分析取得用户命令字*/ if(b=='T') break;/*如果是logout就退出程序*/ switch(b){ case 1:/*切换工作目录*/ if(chdir(cmd + 3) != 0) { printf("chdir(%s) error!%s/n", cmd + 3, strerror(errno)); } printf("I'm working in '%s' now/n", getcwd(tmp, 100)); break; case 2:/*ls命令*/ case 7:/*cp命令*/ case 8:/*pwd命令*/ system(cmd); break; case 3:/*pid命令*/ printf("%d/n", getpid()); break; case 4:/*rm命令*/ remove(cmd + 3); break; case 5:/*mkdir命令*/ mkdir(cmd + 6, 0755); break; case 6:/*mv命令*/ p = strchr(cmd + 3, ' '); *p = 0; rename(cmd + 3, p + 1); break; case 0:/*不能识别的命令*/ printf("Bad command, try again! All aviable commands are:/nlogout cd ls pwd pid rm mkdir mv cp/n", getpid()); break; } } } char parsecmd(char * s) { if(!strcasecmp(s, "logout")) return 'T'; else if(!strncasecmp(s, "cd", 2)) return 1; else if(!strncasecmp(s, "ls", 2)) return 2; else if(!strncasecmp(s, "pwd", 3)) return 8; else if(!strncasecmp(s, "pid", 3)) return 3; else if(!strncasecmp(s, "rm", 2)) return 4; else if(!strncasecmp(s, "mkdir", 5)) return 5; else if(!strncasecmp(s, "mv", 2)) return 6; else if(!strncasecmp(s, "cp", 2)) return 7; else return 0; }

命令运行结下：

Next command% ls / bin cdrom dev home initrd.img lost+found mnt proc sbin sys usr vmlinuz boot data etc initrd lib media opt root srv tmp var Next command% pwd /data/example/c Next command% cd / I'm working in '/' now Next command% pwd / Next command% cd /tmp I'm working in '/tmp' now Next command% pwd /tmp Next command% ls gconfd-administrator ksocket-administrator plugtmp ssh-MmlTLh5149 gconfd-root mapping-administrator scim-helper-manager-socket-administrator virtual-administrator.XSmKSv kde-administrator orbit-administrator scim-panel-socket:1-administrator keyring-g5rmCS orbit-root scim-socket-frontend-administrator Next command% mkdir xxxx Next command% ls gconfd-administrator ksocket-administrator plugtmp ssh-MmlTLh5149 gconfd-root mapping-administrator scim-helper-manager-socket-administrator virtual-administrator.XSmKSv kde-administrator orbit-administrator scim-panel-socket:1-administrator xxxx keyring-g5rmCS orbit-root scim-socket-frontend-administrator Next command% rm xxxx Next command% ls gconfd-administrator ksocket-administrator plugtmp ssh-MmlTLh5149 gconfd-root mapping-administrator scim-helper-manager-socket-administrator virtual-administrator.XSmKSv kde-administrator orbit-administrator scim-panel-socket:1-administrator keyring-g5rmCS orbit-root scim-socket-frontend-administrator ? Next command% logout

【作者: Liberal】【访问统计:】【2007年10月26日 星期五 18:44】【注册】【打印】