Operating Systems & Commands

Here are my notes on the most popular computer systems and the commands to control them, shown side-by-side. Let me know what you find helpful or missing.

Topics this page:

Site Map  
About this site  

Sysinfo by Microsoft and MagniComp details system hardware, software, OS configuration, and storage asset management and configuration data in multiple platform agnostic formats.

Microsoft FAQ on command processor scripts

UNIX for DOS users

Operating System Kernels

Flavor	Product	uname -r	Released
Microsoft
-	IRIX
AT&T	SVR4 (System V Release 4)
Berkeley Software	FreeBSD
-	NetBSD
Hewlett Packard	HP-UX
SunSoft	SunOS	5.8
	Solaris
IBM	AIX
Linux	Red Hat 9	2.4.20-6smp
	Red Hat Enterprise Linux	2.4.21-4.ELsmp
	Mandrake, Caldera, etc.

This comparison of features across Unix implementations from Puppet, a cross-Unix administration tool.

Windows applications, such as Crossover Office, can be run on Linux (with varying success) by using Wine, an open source implementation of the Windows API running on top of Linux OS's.

In the early 1980s, Richard Stallman began the Open Source movement within the software industry by preaching that software should be free in that source code should be shipped with the software product because users:

• should not have to wait for bug fixes to be published by the developer.
• should be able to add features which can be contributed back to the source community for everyone's benefit.
• are not forced to deal with a developer who might or might not support that user's intentions for the software.
• should use code exposed to the scrutiny of many programmers (resulting in higher quality than secret code)

Windows Management Instrumentation (WMI) is based on the Common Information Model (CIM) supported by the Desktop Management Taskforce (DMTF)

Making UNIX and Windows NT Talk by Nadelson, Mark.; Hagan, Tom (Lawrence, Kan. CMP Books, 2000)

Windows 2000 & Unix Integration Guide by Burnett, Steven Forrest.; Gunter, David.; Gunter, Lola. (Berkeley, Calif. McGraw-Hill Professional, 2000)

Linux can serve Windows clients via the Samba package.

Installing Windows clobbers the dual-boot disk created when Linux is installed.

Memconf by Tom Schmidt is a Perl5 script that displays the size of each SIMM/DIMM memory module installed in Sun/HP-UX systems. Listed in the SunManagers FAQ.

Poof! by Kilowatt Software provides 135 Windows command line tools. use it instead of
Microsoft NT Power Toys which has been removed from Microsoft's website.

SlickRun is a free floating command line utility for Windows so that command aliases (known as MagicWords) provide instant access to any program or website.

Command Interpreter Shells -- Their Prompts and History

Shell	Command	Default Prompt	Initialization File	History
MSDOS	cmd	>	AUTOEXEC.BAT	Began as CP/M from Gary Kildall. Purchased by Microsoft in the mid 1970's for the IBM PC. Ended at version 6.22 (7.1 within OEM Windows 95B)
PCDOS	cmd	>	AUTOEXEC.BAT	Jointly developed by Microsoft and IBM until version 5.
-	DRDOS	>	AUTOEXEC.BAT	Developed by Digital Research, then purchased by Novell, then Caldera/Lineo in 1999.
Bourne Shell	sh & bsh	$	.profile	Developed at AT&T by Stephen R. Bourne in the early 1970s. It was the original and official shell distributed by AT&T and its successor, Unix System Laboratories, now owned by Novell. Considered the fastest, most portable, and easiest shell to learn, it lacked command history and command editing. It's what Oracle provides by default. Shell scripts developed for public use are usually written in the Bourne shell language and assume a System V Release 1 environment.
Bourne Again Shell	bash	$	.profile & .bash_profile	Created for use in the GNU project started by Richard Stallman of the Free Software Foundation (FSF) to replace all commercial UNIX utilities with freely distributable copyleft. Written by Brian Fox from Sunday, January 10, 1988 until 1993 when Chet Ramey became the official maintainer.
C	csh	%	.login .cshrc (for settings)	Developed by William Joy (later Sun Microsystems' chief technology officer) and others at UC Berkeley during the early 1980s for C programming flexiblity. Provides the most shortcuts, but is slower than other shells.
Korn	ksh	$	-	Developed by David Korn in the early 1980s. It combines many of the best features of earlier command processors, so is considered a superset of the Bourne shell.
POSIX	sh	$	-	IEEE Std 1003.1 and IEEE Std 1003.2 supported by SunOS and Solaris
Microsoft Shell	msh	>	-	Product code named "MONAD" in the 2004 Longhorn release of Windows provides manipulation of .NET objects and new WinFS type queries. Introduces user-declared System.Management.Automation namespace "commandlets" like unix pipes and "-whatif" directive for testing them.

The C shell and Korn shell is preferred over the original Bourne shell which did not have command history capability.

Shell Feature Comparison

From Unix Unleashed by David Till, et. al.

Feature	sh	csh	ksh	python
Aliasing	-	Yes	Yes
Arithmetic expressions	-	Yes	Yes
Array variables	-	Yes	Yes
Assignment id=string	Yes	-	Yes
case statement	Yes	-	Yes
cdpath searches	SysV	Yes	Yes
-clobber overwrite protect	-	Yes	Yes
Command aliases	-	Yes	Yes
echo -n option	-	Yes	-
export command	Yes	-	Yes
foreach statement	-	Yes	-
getopts built-in command	-	-	Yes
History of commands	-	!n	fc
glob command	-	Yes	-
Hash table problems, rehash and unhash commands	-	Yes	-
Job control (bg, fg, ...)	-	Yes	Yes
let command	-	-	Yes
limit, unlimit commands	-	Yes	-
nice shell built-in	-	Yes	-
nohup shell built-in	-	Yes	-
notify shell built-in	-	Yes	-
onintr command	-	Yes	-
print command	-	-	Yes
pushd, popd commands	-	Yes	-
RANDOM shell variable	-	-	Yes
repeat last command	-	!!	-
Restricted version	rsh	-	rksh
select statement	-	-	Yes
setenv, unsetenv commands	-	Yes	-
SHELL variable specifies command to execute scripts	-	Yes	-
switch statement	-	Yes	-
until statement	Yes	-	Yes
set -x	Yes	-	Yes
set optionname	-	Yes	-
Set-uid scripts	-	-	Yes
Shell functions	SysV	-	Yes
Substring selectors :x	-	Yes	-
trap command	Yes	-	Yes
typeset command	-	-	Yes
ulimit command	Yes	-	Yes
Undefined variable is an error	-	Yes	-
! special character	-	Yes	-
@ command	-	Yes	-
$(...) command expression	-	-	Yes
*(...) wildcards	-	-	Yes
{...} wildcards	-	Yes	-
|& coprocessing	-	-	Yes
>& redirection	-	Yes	-

To be prepared to use various shells, define different temporary folder names. On UNIX systems, use these commands:

$ mkdir /u01/oradata/tmp
$ TMPDIR=/u01/oradata/tmp; export TMPDIR
$ TEMP=/u01/oradata/tmp; export TEMP
$ TMP=/u01/oradata/tmp; export TMP

$80/62 Your Unix 'The Ultimate Guide' (McGraw-Hill, 2001) by Sumitabha Das of Calcutta features 900 exercises for the Bourne, Korn, bash, Linux and C shells
Data files, Solutions manual

The Complete Idiot's Guide to UNIX by Wagner, Bill (Indianapolis, Ind. Alpha Books, 1998)

Checking UNIX Server Performance

UNIX Performance Tuning

UNIX Commands for Tuning AIX

$3 UNIX Shell Programming, 2nd ed. (Hayden Books (Pearson): 1990) by Stephen G. Kochan and Patrick H. Wood

Programming the UNIX Shell 3 week Online course I $295 & II $195

Sams Teach Yourself Shell Programming in 24 Hours by Veeraraghavan, Sriranga (Indianapolis, IN Sams Publishing, 1999)

UNIX Shell Programming Tools by Medinets, David. (New York McGraw-Hill Professional, 1999)

Learning the Bash Shell by Newham, Cameron.; Rosenblatt, Bill. (Cambridge, [England] O'Reilly and Associates, 1998)

Unix Network Management Tools by Maxwell

Unix System Security Tools by Ross

UNIX was not designed to stop you from doing stupid things, because that would also stop you from doing clever things. -- Doug Gwyn

sunfreeware.com offers several "ready to use" Software for SUN Solaris.

Martin Zahn's Sun Tips translated from German

Command Syntax

• A command names an executable file stored in a directory on disk. It is referred to as static because it represents potential action.
• Most commands, with few variations, take the form:
  command [option] [source file(s)] [target file]

• Orthogonal ?
• A program, such as sort, that takes standard input and creates standard output is sometimes called a filter.
• The ampersand (&) at the end of a command requests background processing. The system responds with a process number before returning control of the screen to the user.

  Function	UNIX command	DOS command
  Find commands apropos to given text "HTTP"	apropos "HTTP"
  Get a short description of the command "print"	whatis print
  Read the manual on the command "print" Linux Man Pages on User commands, Sysadmin, devices, File Formats, System Calls, Libc.	man print	help print
  Search manual (whatis database on the MANPATH) for topics beginning with the word &auot;printing"	man -k print
  Clear screen.	clear (or Ctrl+L)	cls
  What version of the kernel am I using?	uname -r	ver
  What directory is the shell located? (e.g., /bin/bash)	echo $SHELL
  What distribution am I using? (e.g., RedHat Linux 9)	cat /etc/issue

Keyboard Operations

Action	UNIX stty	DOS
Alternative to Enter	Ctrl-J or Ctrl-M
Retrieve last command	Esc-K from vi	F3
Clear Screen	Ctrl-L	-
Backspace: Erase last character typed	Ctrl-H or #	Backspace key
Kill all the way back to the prompt (without executing it)	@ or Ctrl-U or Ctrl-X	Ctrl-C
Stop	Ctrl-Z or q	-
Exit / End of file	Ctrl-D	Ctrl-Z
Scroll forward	spacebar
Scroll back	up arrow
Stop scrolling	Ctrl-S
Resume scrolling	Ctrl-Q	Ctrl-Q
Swap Command line to KDE	Alt+F8
Swap KDE to Command line	Ctrl+Alt+F1

More on MS keyboard shortcuts

In the UNIX Korn shell, this command prevents users from being logged off the system when Ctrl-D is pressed:

set -o

Command History

Command history capability enables users to edit command lines and re-execute commands without retyping.

The UNIX BASH shell remembers the last several commands entered in the command line. The number of history events saved depends on the HISTSIZE environment variable. This command history can be viewed by the command prompt:

history

Retrieve specific commands several ways:

• press the UP ARROW or DOWN ARROW at the command prompt
• preceded by "!", enter the event number in the history list
  !49

• enter the offset from the highest entry in the history list. For example, if there were 53 events in the history list, this executes event number 51
  !-3

Unix Users

Login as root when changing system files that, for the sake of system security, should only be changeable by root. These include control of initialization processes, adding a new user, printer, or file system.

There is only one root password. So only one person should have it, but have that written down and stored in a safe.

With UNIX, files installed by a particular user "belong" to that user and cannot be deleted by other users.

If an application is installed by the root user, future changes to the application would require login as root. This forces the distribution of that omnipotent password. More importantly, system change logs cannot log specifically who did what.

Create a non-root admin. account such as "tibco" to install tibco applications:

useradd tibco
passwd tibco

This enables people to sign in with their own individual user account, then upgrade to "superuser" rights:

sudo tibco

The down-side of this approach is that a single shell script cannot perform all functions typically needed in an enterprise deploy that spans several computers. So (error-prone) manual copy of files is necessary.

Cross-dressing Windows as UNIX

Products that run UNIX commands (GNU utilities) on the Windows operating system:

• cygwin.com, which uses an emulation layer.
• UNIX Utils, which depend on the Microsoft C-runtime (msvcrt.dll)
• MinGW (Minimalist Gnu for Windows32) by Colin Peters uses the Microsoft w32api runtime libraries rather than Gnu GPL libraries (for profiling, etc.), so you don't have to disbribute source code.
• MKS Toolkit is a licensed product.
• unixdos.
• Interix (formerly known as OpenNT) is advertised as "a complete UNIX system environment running natively on Microsoft Windows NT", licensed and supported by Softway Systems.

Porting ksh and tcsh Shell Scripts to the Windows Services for UNIX 3.0 (SFU) Interix environment.

UNIX XWindows on Windows

Products such as putty provide command-line access to UNIX boxes.

To see XWindows on UNIX requires additional software such as Cygwin's XServer. Here are the steps:

1. Download Cygwin, install it, and launch a Cygwin window.
2. startx to run XServer which opens a new window.
3. In the new window, type: xhost * to allow connections from all hosts.
4. Open a putty window.
5. In the putty window, type: export DISPLAY=10.1.2.3:0.0 where "10.1.2.3" is your IP address.
6. In the putty window, cd to the install directory and execute the install program that uses XWindows. A new window (e.g., RedHat Gnome interface) should appear.

Unix File Permissions

If you create a UNIX shell script and run it, you will get a "Permission denied" message if you don't explicitly assign execute permissions with a command such as:

chmod +x myscript.sh

Code	Permission	Octal	Decimal
r--	Read only	0100	4
-w-	Write only	0010	2
--x	eXecute only	0001	1
rwx	Read, Write, eXecute	0111	7

In Unix systems, 3 permissions can be granted: read, write, and execute (abbreviated as r, w, and x).

Each permission is stored as one binary bit within a 4-bit number.

Unix commands specify all three permissions at once using the decimal equivalent of the 4 bit "octal" number, so called because one can count to 8 using 4 binary bits.

	-	u user	g group	o other
ls -l	-	rwx	r-x	r--
chmod binary		4+2+1	4+0+1	4+0+0
chmod octal		7	5	4
umask binary		0+0+0	0+2+0	0+2+1
umask octal		0	2	3

command ls -l (with the -long option) lists the 3 permissions for each category of ownership (user, group, other) along with the name of the owner and the KB of its password file.

An octal number is used to store the permission of each category of ownership.

Umask filename without argument echoes current permissions settings as an octal number.

chmod 754 filename sets permissions using "7" for user, "5" for group, "4" for other.

umask 023 filename (user mask) cause all new files to be created as if "chmod 754" were executed after their creation.

chmod ugo+rwx filename sets permissions for all category of ownership.

"-" instead of "+" removes the permissions.

chmod a+r filename sets permissions for all users.

In Solaris, to modify the default group membership of a file:

chgrp group file

CPU Information

To get a list of the CPUs on a machine: On Solaris: /usr/sbin/psrinfo -v

To list the RAM usage for a machine:

Solaris	ptconf|grep -i mem	project/task level
	ptconf|grep -J mem	processes and tasks
	psrinfo -v	-
HP/UX	swapinfo -tm
IBM AIX	lsdev -C|grep mem lsattr El mem0
DEC-UNIX	uerf -r 300 | grep -i mem
Linux	free

Related page: The Windows Management Interface.

Determining CPU RAM Installed

Each operating system has its own command to determine the amount of physical memory installed:

AIX	lsattr -El sys0 for the "realmem"
Compaq Tru64	vmstat -P for the "Total Physical Memory"
HP-UX	dmesg for the “ Physical:”
Solaris	/usr/sbin/prtconf | grep Memory for "Memory size"

To determine the size of each memory page:

# /usr/bin/pagesize
8192

To determine the amount of memory used (by the kernel, Anon, Exec, libs, cache, free):

On Solaris: mdb -k

Machine Control Commands

Action	UNIX options & filespec	DOS filespec & options
Reboot / re-start	reboot	-
Shut down (halt) machine abruptly	poweroff halt -p shutdown -h now init 6	-
Shut down (halt) machine gracefully	shutdown -ry 10 -a to Use file /etc/shutdown.allow -c to cancel scheduled shutdown.	-
Elapsed time (and other statistics) since last reboot	uptime	NET STATISTICS
List installed patches	showrev -p patchadd -p	-

Network Control

Action	UNIX options & filespec	DOS filespec & options
View computers on a network:	?	NET VIEW
List shares on a given machine:	?	NET SHARE
List user accounts on a given machine:	?	NET USER
List user sessions on a given machine:	?	NET SESSION
Add computer “homer” to the PDC on the local domain:	?	net computer \\homer /add

Processes/Services/Daemons

A process is a sequence of actions that take place in memory. It is referred to as active because it is the work the computer does in response to the execution of commands.

Action	UNIX options & filespec	DOS filespec & options
List Windows services/UNIX processes (daemons):	pstree ps -aux	NET HELP START
Start service/process	-	NET START service
Stop service/process	-	NET STOP service
Pause and continue started services:	pstop 22121	NET PAUSE service NET CONTINUE service
Kill process	pkill HUP in.named	Microsoft does not provide a built-in command to stop processes. However, Command Line Process Utility Freeware by Craig Peacock does the job. Alternately, pskill from sysinternals is a simpler (less featured) freeware

Forking Processes

To fork processes:
cmd1 || cmd2 # exec cmd2 if cmd1 fail cmd1 && cmd2 # exec cmd2 if cmd1 is OK

This example uses tee to send 1>stdout and 2>sterr separately and also both together so you can see when each occurred with respect to each other:

((./program 2>&1 1>&3 | tee ~/err.txt) 3>&1 1>&2 | tee ~/out.txt) > ~/mix.txt 2>&1

Disk Utilities

Function	UNIX command	DOS command
Total Disk Usage (in 512 byte blocks)	du -s	chkdsk
Disk Usage for directories -in kilobytes	df -kah	-
Disk Usage for each file	du -lR -a	-
Disk Quota information	DQinfo	-
Disk Quota allocation	DQalloc	-
Disk Quota removal	DQrm	-
Repartition FAT disk	Linux fips.exe
Reformat disk drive system	mke2fs	format

Using DOS Floppies within Linux

Folder Locations

Function	Linux	Microsoft
Kernel	root /boot	"WINNT" or "WINDOWS"
Executables	/usr/bin /usr/lib /usr/include /usr/share /usr/doc /usr/apps	"Program Files"
Drivers	/dev	Win.../System32
hosts file	/etc	Win.../System32/Drivers/Etc
One for each User	/usr /user	"Documents and Settings"
Log files	/var	-
Temporary work files	/tmp	Temp
Optimizing Utilities	/opt	-

To get a list of libraries mapped into processes on Solaris: pldd $$

Folder/Directory Commands and Options

Action	UNIX options & filespec	DOS filespec & options
Check current Print Working Directory	pwd	cd
Return to user's home folder	cd cd ~	cd /
Up one folder	cd ..
Make directory	mkdir proj1
Remove empty directory	rmdir /usr/sam	rmdir or rd
Remove directory -recursively	rm -r	rmdir /s (NT) deltree (Win 95)

File Listing Commands and Options

Action	UNIX options & filespec	DOS filespec & options
List directory tree -recursively	ls -r	tree
List last access dates of files, with hidden files	ls -l -a
List files by reverse date	ls -t -r *.*	dir *.exe /o-d
List files verbosely by size of file	ls -l -s *.*	dir *.* /v /os
List files recursively including contents of other directories	ls -R *.*	dir *.* /s
List file types in color	ls -flai --color
List number of lines in folder	wc -l *.xtuml sed -n '$='	sed -n "$="
List files with x anywhere in the name	ls | grep x

File Type Indicators

The "ls -l" command lists permissions for both files and directories. An example:
drwxr-xr-x 3 richard punks 2048 May 13 09:27 public

Linux	UNIX	File Type	Color	test
blank	-	Regular/normal file	White	-f
/	d	Directory/folder	Blue	-d
*		Program or executable script	Green	-x
|	p	Named (fifo) Pipe		-p
@	l	Symbolic link	Aqua	-h
=		Socket
	b	Block special file		-b
	c	Character special file		-c

The test command also uses -s for nonzero size, -w for writeable by the current user, -a for ???

Use the --color parameter to always see in color:
alias ls='ls --color'

For no color

unalias ls

An inode number is the address of a disk block. Two filenames with the same inode means they are aliases of the same physical file.

To create a hard file link (within the same directory):

ln         file1   file2

To create a symbolic link:

ln   -s   file1   file2

File Attributes

Microsoft uses the first letter of each attribute name (read-only, archive, system, hidden):
Attrib [+r¦-r] [+a¦-a] [+s¦-s] [+h¦-h] [path\file] /s

/s specifies processing of all downstream subdirectories as well.

To remove read-only and hidden attributes from myfile located in mypath:

Attrib -r -h \mypath\myfile

File Manipulation Commands and Options

To obtain a file from the internet using HTML:

wget http://drupal.org/files/projects/drupal-x.x.tar.gz

Having a bunch of these in a batch file is how you automate downloads instead of right-clicking on a link and selecting "Save Target As...".

Action	UNIX options & filespec	DOS filespec & options
To untar a tar file (used in UNIX but not recognized by WinZip8):	tar -zxvf file	not WinZip
To unjar a jar (Java archive) file	jar -xvf file.jar	Winzip?
Page the contents a screen at a time: spacebar forward, B for Backward, Q to Quit	less   afilename
Peek at the first and last n lines	head -n file tail -n file	TYPE x.txt | MORE
Create new (blank) file	touch afilename
Copy old.file to new.file -p preserve file attributes (e.g. ownership and edit dates) -r copy recursively through directory structure -a archive, combines the flags -p -R and -d	cp old.file new.file	copy old.file new.* xxcopy
Move old.file (-i interactive flag prompts before overwriting files)	mv -i old.file /tmp	Copy old.file /tmp del old.file
Remove file (-intention)	rm -i sam.txt	del sam.txt
Find and (blindly) remove files in the system with file types of tmp which haven't been accessed in the last 10 days	find / -name "*.tmp" -atime +10 -exec rm {} \;	-
Find and prompt user mike to OK removal of files in the system with file types of tmp	find /usr/home/mike -name "*.tmp" -ok rm {} \;	-
Find and print user files in the system with file types of txt	find /usr/home -depth -name "*.tmp" -print	edit file.txt
Compare two files and show differences	diff	comp fc

Redirection & Piping

Each program can perform a very specific task when the datastreams from one program can be redirected to a device or piped into another command process ( like connecting garden hoses).

Redirection & Piping Action	UNIX
Read STDIN file feed.txt and output STDOUT to file x.txt and STDERR to file err.txt There is no space between the number and >. Specifying the same file for both input and output erases that file.	readnews 0>feed.txt 1>x.txt 2>err.txt
outputs to nowhere Do not use vi or touch commands on /dev/null. This turns it into a file, which confuses Linux start-up scripts.	readnews > /dev/null
count entries starting with "a" from a listing	ls -l | grep d? | wc
input file schedule into the mail program to output file acctng	mail acctng < schedule
Appends output of command to the bottom of AppendedFile.	command >> AppendedFile
Concatenate 3 files and pipe to line printer and tee (replicate) it to the screen as well.	cat file.1 file.2 file.3 | tee lp

File Utilities

Action	UNIX options & filespec	DOS filespec & options
View a file	vi file.txt EMACS	edit file.txt
Edit file	pico myfile	edit myfile
view file starting at line number 39	more +39 whatever.txt
Format text for printer	troff file.txt nroff file.txt
Compact (defragment) files		compact
Concatenate files	cat file1 file2 to standard output.	copy file2 >>file1
Counts -lines, -words, and -characters in a file	wc -l
Displays line-by-line differences between pairs of text files.	diff
calculator	bc
calendar for September, 1752 (when leap years began)	cal 9 1752

WinBatch from Morrie Wilson WindoWare of Seattle compiles makes executable runtimes from macro scripts written using its own “Windows Interface Language” for controlling Windows and Windows NT and Novell Netware clients.

ZDNet Article

MIcrosoft's Windows Scripting Host

/rdb from Revolutionary Software is a commercial product ($249 for Linux/BSD $495 for Sun/AIX/HP/Windows) implemented as a suite of 131 UNIX shell level commands. It's described in UNIX relational database management: application development in the UNIX environment and the 1988 UNIX Relational Database Management, both by Rod Manis, Evan Schaffer, and Robert Jorgensen.

Symbolic Links

UNIX OSs allow a "virtual" name that "redirects" references to that name to a physical file.

To create a symbolic (pointer) link called "FileX" to "RealFile":

ln -s /home/user/Realfile FileX

Regular Expressions

Pattern Matching

	Pattern	Example
Position	? stands for any single character	ls ?1
Position	* stands for any number of characters	ls 2*
Specific characters	[AB] stands for any number of characters	ls [AB]1 would yield A1 and B1
Range of characters	[A-Z] stands for letters from A thru Z

The MS-DOS CLI command Comp compares the contents of two files or two sets of files. Its syntax:

Comp [files1] [files2] [/d] [/a] [/l] [/n=number] [/c]
where
files1 and files2 are the file sets for comparison.
/d yields a decimal display.
/a yields an alpha display.
/l shows the line numbers for differences rather than offset.
/n forces the line-by-line comparison for n lines, even in different length files.
/c removes case sensitivity.

Usage Example:

Comp \path1\myfiles \path2\myfiles /l

compares the files in \path1\myfiles with those in \path2\myfiles and show just the line numbers of any discrepancies.

The MS-DOS CLI command FC (file compare) two individual files and displays content discrepancies. Its syntax:

Fc [/a] [/b] [/c] [/l] [/lbx] [/n] [/t] [/u] [/w] [file1] [file2]
where
files1 and files2 are the file for comparison.
/a yields an abbreviated display of discrepancies.
/b specifies a binary compare (ASCII is the default for files not having a binary extension).
/c means case-insensitive.
/l is the ASCII compare for files having a binary extension (such as .exe).
/lbx buffer size (the x part) for how many discrepancies Fc should tolerate before exiting.
/n shows line numbers during ASCII compare.
/t skips expanding tabs to spaces.
/u performs unicode compare.
/w skips consecutive whitespaces.

The MS-DOS CLI command findstr (find string) in an individual file. Its syntax:

Findstr [/b] [/e] [/l] [/c:mystring] [/r] [/s] [/i] [/x] [/v] [/n] [/m]
where

/b finds pattern at start of line.
/e finds pattern at end of line.
/l uses literal find pattern.
/c:mystring is the string to search for.
/r (default) searches for non-literal strings.
/s also searches subdirectories.
/i is insensitive for case.
/x shows exact matching lines only.
/v shows non-matching lines only.
/n prints line numbers.
/m shows matching files only.

sed (stream editor)

sed works like a find-and-replace filter. Its general format is: 's/ regexp / replacement / flags'

This sample command from a FAQ) produces a newfile after replacing every occurrence of "Glenn" with the word "Harold":

sed 's/Glenn/Harold/g' oldfile >newfile

F. Curtis Michel Introduction to sed says:

"you will almost NEVER get the command line right the first time!"

"regex" ("Glenn" in the example above) is a regular expression pattern. More examples:

$d               # delete the last line of the file
/[0-9]\{3\}/p    # print lines with 3 consecutive digits
5!s/ham/cheese/  # except on line 5, replace 'ham' with 'cheese'
/xyz/!s/aaa/bb/  # unless 'xyz' is found, replace 'aaa' with 'bb'
17,/foo/d        # delete all lines from line 17 up to 'foo'

awk

Example: to extract some part of the content of a line searched, and rename the previous output file to the text found:

awk 'BEGIN{FS=":"}/^DnsName/{print $2}' outputfile > newfile

$63/$26 The AWK Programming Language (Addison-Wesley (Pearson): 1988) by Alfredo V. Aho, Brian W. Kernighan, and Peter J. Weinberger

AWK

text2html.awk converts a text file to html.

Randomizers

Ksh provides a variable to generate a random number between 0 and 32767:

echo RANDOM=$RANDOM
SECONDS # The number of seconds since the shell was invoked

Iteration in Shell Scripts

With Windows Shell scripts set the default script host so you don't have to type cscript before each .vbs file execution:

Cscript //h:cscript //s

A sample DOS script to invoke the "Ping of Death" to crash your machine:


@echo off
CLS
REM Start Task Manager:
start /high /min taskmgr.exe
REM
REM Launch Internet Explorer to a site:
start /high http://www.microsoft.com/
REM
REM Invoke the ping of death to crash your machine:
for %%d in ( A B C D E F G H I J K L M N O P Q R ) do start /min ping -l 65527 -n 1000 localhost

while ... do ...

if who | wc -l > 1 ; then echo "There is 1 user"; else echo "There are x users" ; fi

Related: