Article 148285 of comp.os.vms:
OpenVMS Commands with unix equivalents

OpenVMS				unix		Explanation/examples
=========================================================================
APPEND				cat		Concatenates files.  If contencs of file1 need to be placed at the end of file2 issue the following unix command.cat file1 >> file2
ASSIGN or DEFINE		= 		(Bourne & Korn)set (C shell)	in Bourne or Korn shell DIR = lsin C shell set DIR ls
ATTACH				fg	
BACKUP				tar or pax	back up files into a tar file.
  /INIT				tar -c or pax	Restore files.
  /LIST				tar -t		List contents.
  /LOG				tar -v		Report progress.
  /NOREWIND			tar -r		Write at end of existing backup (tar) files.
  /RECORD			tar -m		Update file’s modification date upon restore.
COPY				cp		Copy a file 
COPY				ftp		Copy to/from a nontrusted remote host.
COPY				rcp		Copy to/from a remote host.
COPY /CONFIRM			cp -i		Confirm before copying.
CREATE				touch		Create or update a file.
  /DIRECTORY			mkdir		Create a subdirectory.
CREATE filename			cat << filename	Create a file from the keyboard.
CREATE filename			cat	
DEBUG				dbx		Debug a program.
DELETE				rm		Delete a file.
DELETE				rmdir		Delete an empty subdirectory.
  /CONFIRM			rm -i		Confirm deletion.
  /ENTRY			lprm		Remove queued line printer job.
  /QUEUE			lprm -P		Remove all jobs from the queue.
  /LOG				rm -e		Delete files and list them as they are deleted.
  /SYMBOL			unset		Get rid of an environment variable.
DIFFERENCES			diff		Display all differences in files or directories.
  /MAXIMUM_DIFF= 1		cmp		Display first difference in two files (typically used with binary files).
  /NUMBER NL:			cat -n	Display a file with line numbers.
  /SLP				diff - e	Generate editing changes for the ed editor.
DIRECTORY			ls		List files.
DIRECTORY [...]			ls -R		Do a recursive directory/list of files.
DIRECTORY [...]			find		Find a file
DIRECTORY *.DIR			ls -d		List directory name(s) only ls -Rd
  /BY_OWNER			ls -l dir | grep owner	List only those files owned by a specifed user.
  /COLUMN			ls -1		List one file per line.
  /DATE				ls -c		List by creation/last modification.
  /FULL				ls -l		Long listing.
  /FULL /TOTAL			du		Summarize disk usage.
  /MODIFIED /SINCE [...]	find -mtime +n	Modified more than n days ago.
  /MODIFIED /BEFORE [...]	find -mtime +n	Modified more than n days ago.
  /OWNER			ls -g		Include group (used with |).
  /SIZE				ls -s		Include size.
DISMOUNT /UNLOAD		mt rewofmt offline	Rewind and unload the tape.
DUMP				od		Dump a file in various formats.
  /HEXADECIMAL			od -h		Hexadecimal dump.
  /OCTAL			od -o		Octal dump.
EDIT /EDT,EDIT /EVE, EVE	vi		Screen editor session.
EDIT /RECOVER			vi -r		Recover a screen editing session.
EXCHANGE			dd		Back up, restore, and convert nonstandard files.
EXIT				exit		Terminate a script.
HELP				man		Display online reference pages. 
HELP HINTS			man -k topic	Display a list of commands that correspond to the specified topic.
INQUIRE /NOPUNCTUATION		read choice? 	Prompt for a responce and put the response into an environment variable.
INITIALIZE device:		fddisk -fmt device	Format a diskette.
LIBRARY				ar		Library maintainer.
  /CREATE			ar -cr		Create library.
  /EXTRACT			ar -x		Extract modules.
  /INSERT			ar -q		Insert modules.
  /LIST				ar -t		List modules.
  /REPLACE			ar -r		Replace modules.
LINK				ld		Link compiled source code into an executable image.
login procedureLOGIN /CLI	.login.cshrc.profile.kshrc	Set of commands automatically executed at login time.  On OpenVMS, LOGIN/CLI specifies an alternate command language interpreter.
LOGOUT				logout C shellexit Bourne & Korn shell	Terminate a terminal session.
MAIL				mail		Invoke the mail utility.
MERGE				sort -m		Merge sorted files.
MOUNT				mount		Mount a tape.
ON COUNTROL_C THEN		trap 2		Enable handler for Stop signal.
ON CONTROL_Y			onintr		On interrupt.
PHONE				talk tty	name	Communicate interactively with another user.
PRINT				lpr		Print a file on the default line printer.
  /COPIES=N			lpr -#n		Print n copies.
  /DELETE			lpr -r		Remove file after printing
PRINT commands cont.		
  /FORM				lpr -ln		Make page n lines (default = 66)
  /FORM				lpr -n		Print n column output.
  /FORM				lpr -wn		Set line width to n
  /HEADER			pr -h string | lpr	Print a header on each page.
  /NAME=jobname			lpr -Jjobname	Include job name on the first page of the job.
  /NOFLAG			lpr -h		Print with no header page.
  /NOTIFY			lpr -m		Send mail upon completion.
  /PAGES=(n,””)			lpr +n		Begin printing on page n.
  /QUEUE			lpr -Pqueue	Print a file on the specified queue.
READ				read		Read input (korn shell)
RECALL /ALL			history		Recall command lines
REPLY /USER			write		Send a brief message to a logged-in user
RENAME	mv			move/rename a file(s)
   /CONFIRM			mv -i		confirm the move/rename of a file(s)
SEARCH				grep		Search files for strings.
   /MATCH=NOR			grep -v		List only lines that do not match
   /NOEXACT			grep -i		Ignore case distinctions.
   /NUMBERS			grep -n		Precede each match with line number.
   /STATISTICS			grep -c		List only a file name that contains match
  /WINDOW = 0			grep -l		Return only file name(s) that contains match
  file pat’rn /WINDOW=5		more -5 	+/pat’rn file	Display search line plus two lines before and after. (Terminate with q).
  file pat’rn /WIND=(5,0)	cat file | more -5+pat’rn	Display search line plus next five lines.
SET DEFAULT			cd		Change directory.
SET FILE/OWNER			chgrp		Change group ownership of a file.
SET HOST			rlogin		Network login to trusted host.
SET HOST /DTE			tip		Dial remote host.
SET HOST 0 /LOG			script		Record a transcript of a terminal session.
SET PASSWORD			passwd		Change you local password.
SET PROCESS /PRIORITY		nice or renice	Change the priority of a process.
SET PROTECTION			chmod		Change file protection.
   /DEFAULT			umask		Change default protection for files not yet created.
SET TERMINAL			tset or stty	Set terminal characteristics.
SET VERIFY			ksh -x orcsh -x	Verify command or script execution.  Echo after variable substitution.
SHOW DEFAULT			pwd		Display current directory.
SHOW DEVICE /FULL		df filesystem	Display information on a file system
SHOW LOGICAL			printenv	Display environment characteristics.
SHOW PROCESS /ALL		ps -l		Dislay all processes on system.
SHOW /QUEUE			lpq		Display default print queue status.
SHOW STATUS			time		Display resources used by a process.
SHOw TIME			date		Display date and time
SHOW USERS			who		Display the list of current system users.
SORT				sort		Sort and merge.
   /KEY	sort 			   +fskip.cskip /-fskip.cskip	Starting/ending porint of sort key.
   /OUTPUT			sort -o file	Direct output to file.
SPAWN /NOWAIT			bg		Move a process to the background.
STOP /ID			kill -9		Remove a process.
SUBMIT				at		Start a process at a latter time.
TYPE				cat		Display a file
   /PAGE			more		Display a file, pausing after each page.
   /PAGE NL:			clear		Clear the terminal screen.
WRITE				/bin/echovar > file	Create a file and write a string or the contents of a variable to it.
WRITE				/bin/echovar >> file	Append a string or the contents of a variable to an existing file.
WRITE SYS$OUTPUT		echo (c Shell)print (Korn)	Write to standard output.

OpenVMS Mathematical Operators Function Equivalents
====================================================
OpenVMS		unix	Explanation
.EQ., .EQS.	==	Equal to
.NE., .NES.	!	Not equal to
.AND.		&&	Boolean and
.OR.		||	Boolean or
.GT., .GTS.	>	Greater than
.GE., .GES.	>=	Greater than or equal to
.LT., .LTS.	<	Less than
.LE., .LES.	<=	Less than or euqal to
+		+	add
-		-	Subtract
*		*	Multiply
/		/	Divide
var + 1		var++	Increment by 1
var - 1		var--	Decrement by 1
		%	Modulo
		>>	Right bit shift
		<<	Left bit shift
.NOT.		~	1’s complement
.NOT.		!	Logical negation
.OR.		|	Inclusive OR
		^	Exclusive OR
.AND.		&	And

OpenVMS Lexical Function and unix Equivalents
=============================================
OpenVMS					unix		Explanation
F$ENVIRONMENT(“INTERACTIVE”)		tty -s		Determine if you are an interactive user.
F$EXTRACT(start, length, string)	cut -c		Locate fields in a test string and write them out.
F$ELEMENT(element#, delimiter, string)	cut -f -d awk	Locate delimited fields in a test string.
F$ENVIRONMENT(“PROCEDURE”)		$0 (Korn)$arg [0] (C)	Get name of currently executing script.
F$TRANSLATE(“SYS$SYSDEVICE”)		sizer -r	Get name of the device from which the operating system bootstrapped.
F$GETDVI(“TT:”, “DEVNAM”)		tty -s		Determine the name of the terminal you are using.
F$GETSYI(“HW_NAME”)			sizer -c	Get model name of the CPU
F$GETSYI(“HW_MODEL”)F$GETSYI(“CPU”)	sizer -wt	Return workstation device type
F$GETSYI(“VERSION”)			sizer -bstrings /vmunix | grep ‘(Rev’uname -a	Determine booted kernel’s file name and system version.
F$GETSYI(“PHYSICALPAGES”)		uerf -r 300 -R | grep physical (+2)wc -c/dev/mem	Get the physical memory on a system.
F$GETSYI(“BOOTTIME”)			who -b	Get system boot time.

 unix Branching statements
DCL command procedures rely on the statements if, gosub, call, and goto for program branching.  The shells under unix offer several branching statements.

Shell	Branching Statements Offered
====================================
csh	if, goto, while, foreach, switch, shift
ksh	do, case, elif, for, function, if, select, time, until, while
sh	if, for, while, until, case

Debugging Shell Scripts
Debugging of shell scripts is done by invoking ksh or sh scripts with the -x and -v flags.  Debuging of C shell scripts by invoking them with the -v, -V, -x or -X flags.  The result is like using the OpenVMS command set verify.