... 205
BASH_ ARGC 205
BASH_ ARGV 205
BASH_ CMDS 206
BASH_ COMMAND 206
BASH_ EXECUTION_STRING 206
BASH_ LINENO 206
BASH_ REMATCH 206
BASH_ SOURCE 206
BASH_ SUBSHELL 206
BASH_ VERSINFO 207
BASH_ VERSION ...
Administration Recipes
Beginning Portable Shell Scripting
Expert Shell
Scripting
Pro Bash
Programming
Beginning Perl 2nd Edition
Beginning Ubuntu LTS Server
Administration 2nd Edition
trim ... 219972
5 34 9 9
Pro Bash Programming:
Scripting the GNU/Linux Shell
Dear Reader,
The shell is a programming language! A shellscript is as much a program as
anything written in C, Python, or any...
... $OSTYPE in
"LINUX" )
PING=/usr/sbin/ping
;;
"FREEBSD" )
PING=/sbin/ping
;;
"SOLARIS" )
PING=/usr/sbin/ping
;;
*)
;;
esac
}
Using Your Library
Once you’ve included ... quote
your string variables to gracefully handle an undefined variable or white space within
the string. A comparison involving an unquoted, undefined string variable in the bash
shell will return ... With this increased output, you can easily view what is happening in the run-
ning script and possibly determine where your problem lies.
When you put the instruction set -x into your script, each...
... LOCKED ++
++ IN $REMAINING day\\(s\\) ++
==============================================================
If the password isnt changed within $REMAINING day\\(s\\), account will be locked.
Instructions ... to environment variables and contains customizable
elements so the message can be tailored specifically to the recipient.
In Chapter 36, I present a script that checks every morning for user ... morning for user passwords that are
aging and therefore should be changed. In that script, when a password has reached the
predetermined cut-off age, the script sends an e-mail to the account...
... troubleshooting. Indenting them with the normal code makes them
more difficult to find when I want them removed.
CHAPTER 1
■
SHELLSCRIPT DEBUGGING
9
If these three lines were executed in a script, ... 1
■
SHELLSCRIPT DEBUGGING
7
valuable in tracing through the running of a script, it can be cumbersome to isolate the
exact piece of data that you’re looking for. With an echo or print statement, ... displayed if the script were run without
tracing enabled. As you can see, this type of trace is highly useful in determining the value
that variables contain during the execution of a script, as...
... Common Linux Shells
Shell
name
Program
name(s)
Description
ASH
shell
/bin/ash
/bin/bsh
Resembles the shell used by AT&T's System V
Unix.
BASH
shell
/bin /bash
/bin /bash2 ... preparing you for an in- depth, continuing study of Linux.
13.1 The Linux Shell
You met the Linux command interpreter, or shell, early in this book. Like an
MS-DOS Prompt window, the shell ... powerful BASH shell, providing a much more
detailed explanation than that provided in Chapter 4, Issuing Linux
Commands. The chapter also briefly explains shell variables, shell scripts,
and shell...
... tin về loại shell nào đợc sử dụng. Mỗi khi bạn login, hệ thống sẽ đọc tệp này để lấy
thông tin khởi tạo cho shell.
Thông tin có thể gồm một trong những dạng sau:
/bin/sh Bourne shell
/bin/jsh ... hiện nay Linux là một hệ điều hành kế thừa của Unix. Linux cũng có những
shell tơng tự và bạn có thể sử dụng những giới thiệu về shell ở đây với các hệ thống Linux.
3. Những loại shell hiện ...
/bin/sh Bourne shell
/bin/jsh Bourne shell, có thêm phần điều khiển tác vụ (job control)
/bin/ksh Korn shell
/bin/csh C shell
Bạn có thể thay đổi shell mặc định sang một loại khác bằng...
... tin về loại shell nào đợc sử dụng. Mỗi khi bạn login, hệ thống sẽ đọc tệp này để lấy
thông tin khởi tạo cho shell.
Thông tin có thể gồm một trong những dạng sau:
/bin/sh Bourne shell
/bin/jsh ... hiện nay Linux là một hệ điều hành kế thừa của Unix. Linux cũng có những
shell tơng tự và bạn có thể sử dụng những giới thiệu về shell ở đây với các hệ thống Linux.
3. Những loại shell hiện ...
/bin/sh Bourne shell
/bin/jsh Bourne shell, có thêm phần điều khiển tác vụ (job control)
/bin/ksh Korn shell
/bin/csh C shell
Bạn có thể thay đổi shell mặc định sang một loại khác bằng...
... P<#M//B
Q#0:##
K##0:R;<
N
K##%
K##+%
K##K%
Mng trong shell script
ã
Mng:
ã
Tp hp cỏc giỏ tr d liu c lu tr qua mt tờn
chung
ã
Ging nh bin: khụng cn khai bỏo trc khi s
dng
ã
c t ng to ra qua ... linux
q/D9BrSsH0@BAA:
LH0@BA/`M7
LH/heA:7
LG@?)H@7
LHtSBH777
Tỡm kim
A.
ã
Tỡm mt file trong mt cõy
ã
Cu trỳc:
find [path] [expression]
ã
Cỏc tựy chn:
ã
name
ã
-print
ã
type
ã
-mtime
ã
exec
ã
ok
Dch v cron
NbD<VtB}#TUSA;VW
~A:ã#H=#VWWl
Vu0*FD<=>G
227/<
227/<
227B/<
227#/<
LH=#S;./85eV=c@VT
H#0HVtB}#h*`S;@9*9XH5
D<7
... trình
LH-5A:V=coGD
w<7
x
yH5BCVTS;BCDH-5
x
x
z=cBCDMCB//`SIBCVT
x
Le#{-5BHA:7
x
<
x
z=cBCDMC
x
yE/r#/7
x
/yE/rVu9*
x
0//PBVv9*;8
Hệ thống log trong linux
q/D9BrSsH0@BAA:
LH0@BA/`M7
LH/heA:7
LG@?)H@7
LHtSBH777
...
... must be printed. Test your script as
$ Q12 /bin
$ Q12 /bin/*
Answer: See Q12 shell Script
Q.13. Write script to print contains of file from given line number to next given number of lines. For ... command line argument in our script.
Lets take ls command
$ ls -a /*
This command has 2 command line argument -a and /* is another. For shell script,
$ myshell foo bar
ShellScript name i.e. myshell
... string2
string1 != string2 string1 is NOT equal to string2
string1 string1 is NOT NULL or not defined
-n string1 string1 is NOT NULL and does exist
-z string1 string1 is NULL and does exist
Shell also test...
... product training.
The Pelco Global Training Institute offers instructor–led courses at three training centers
in North America, including Pelco’s headquarters in Clovis, CA, and seven training centers ... needed.
PELCO GLOBAL
TRAINING INSTITUTE
At the heart of the PGTI are our Instructors, Field Trainers,
and Instructional Designers. Mechanical and Electrical
Engineers, certified networking specialists, ... considered 15.0
16.0 | DESIGNING A SYSTEM 16.0
Some Points To Consider When Investing In A Network
Based Video Security System 16.0
17.0 | PELCO GLOBAL TRAINING INSTITUTE 17.0
...
... and in different formats.
How to do it
echo is the basic command for printing in the terminal.
www.it-ebooks.info
Shell Something Out
8
In this book we are dealing with Bash (Bourne Again Shell) , ... chapter explains how to generate large size les, installing a le system on les
and mounting les, nding and removing duplicate les, counting lines in a le, creating ISO
images, collecting details ... scripting, sending messages to users, bulk image resizing, accessing MySQL databases
from shell, and so on.
www.it-ebooks.info
Linux Shell Scripting Cookbook
Copyright â 2011 Packt Publishing
All...