26. The lpc utility is the main one used to manage the print service,while lpq is the primary tool for looking at and interacting with the print queue.
27. The lpr command is used to submit jobs to the print service, and there are a wide number of options that can be used with it, including:
-b to suppress a banner
-K to specify a number of copies to print
-# the same as -K
-m to send error messages via mail
-T to signify a title page
-w to define the width
28. The /etc/printcap file is a database defining what each known printer is capable of. It is read once by lpd at starup.
29. The lpd.perms file hods the permissions for the lpd service and can affect the operation as such utilities as lpc and lpq.
30. The lpd.conf file is used to configure the actual lpd service. There are 180 options that can be configured.
31. The lprm command is used to remove print jobs, and lprm -a will attempt to remove all spooled jobs.
32. /etc/profile在用户登陆时被执行,然后不同的SHELL会执行用户home下的对应配置文件.如bash依次查找.bash_profile, .bash_login和.profile.
33. .bashrc在SHELL运行开始时被执行. .inputrc用于键盘配置.
34. SHELL脚本必须有可执行权限,或是直接被SHELL读入执行. 0代表正常退出.
35. SHELL脚本中应用"#!"说明解释器位置(如#!/usr/bin/perl)
36. $1代表第一个命令行参数. shift命令将$2变为$1,依此类推.
37. test或者[]可用于进行逻辑测试. if-fi构成判断块.
X窗口
38. "X -showconfig"显示X的配置情况. startx用于启动X窗口.