====== [CHEATSHEET] OpenVMS ======

====== Main concepts ======

===== Keywords =====

^ sort code ^ Full name ^ Translation to linux ^
| UAF | User authorization File | It's a combination of ''etc/passwd'', ''etc/group'' and SElinux/DB concepts with grants and roles |
| UIC | User Identification CODE | ''UID'' the user identificator, in OpenVMS is ''[1,100]''. As in linux should **NOT** be unique |
| DCL | Digital Command Language | ''bash'' LOL |
| CDU | Command definition utility | It's a kind of IDE or ''getops'', allow command line definitions |
| RMS | Record Management Services | ''journalctl'' (logs) |
| JBC | Job Controller | Queues |
| Symbol | - | A variable... |


===== key concepts =====

^ OpenVMS ^ Linux ^ Comment ^
| ''SYS$MANAGER:SYLOGIN.COM'' | ''/etc/bashrc'' |
| ''SYS$LOGIN:LOGIN.COM'' | ''${HOME}/.bashrc'' |
| ''CTRL/Y'' | ''CTRL+C'' | when writing a command and you have a mistake, cancel the input (similar to ''sqlplus'' and ''CTRL+C'') |
| ''CTRL/Z'' | ''CTRL+C'' | Similar but on a interactive input prompt (running a cmd in interactive input mode) |
| ''!'' | ''#'' | comment delimiter |
| ''%'' | ''nothing here'' | Error message delimiter |
| ''^-(.*)'' | ''nothing here'' | Continue a message. For example 1st line begin with ''%'' and 2nd line with ''-'' |


===== Error levels =====

^ alpha ^ numeric ^ level ^
| ''-S-'' | ''1'' | Success |
| ''-I-'' | ''3'' | INFO |
| ''-W-'' | ''0'' | Warning |
| ''-E-'' | ''2'' | Error |
| ''-F-'' | ''4'' | SEVERE |

====== Programming ======
More or less
===== Symbols (Variables)  =====

^ Creation ^ Description ^
| ''SYMBOLNAME = <value> '' | Creates a **local** symbol (string or integer) |
| ''SYMBOLNAME == <value> '' | Creates a **global** symbol (string or integer) |
| ''SYMBOLNAME := <value> '' | Creates a **local** STRING symbol |
| ''SYMBOLNAME :== <value> '' | Creates a **global** STRING symbol |
| ''DELETE/SYMBOL SYMBOLNAME'' | Destroy local variable''SYMBOLNAME'' |
| ''DELETE/SYMBOL/GLOBAL SYMBOLNAME'' | Destroy global variable ''SYMBOLNAME'' |
| ''SHOW SYMBOL SYMBOLNAME'' | Show content of the variable ''SYMBOLNAME'' |

===== Aliases through symbols =====
Create an alias ''EDT'' with a frequently used command:
<code DCL>
EDT :== EDIT/EDT/COMMAND=SYS$LOGIN:EDTINI.DDT
</code>


Replace a command with the command you want:
<code DCL>
PRINT :== PRINT/NOBURST/NOFLAG/NOTRAILER/NOTIFY
</code>
This will replace the command ''PRINT'' with ''PRINT/NOBURST/NOFLAG/NOTRAILER/NOTIFY'' everytime you launch it.

===== Operations with symbols =====

==== Arithmetic operations (integers) ====

<code DCL>
$ APPLES = 10
$ SHOW SYMBOL APPLES
  APPLES = 10    Hex = 0000000A    Octal = 00000000012

$ APPLES = 2 * (4+5)
$ SHOW SYMBOL APPLES
  APPLES = 18    Hex ...
$ ORANGES = 15
$ TOTAL_FRUIT = APPLES + ORANGES
$ SHOW SYMBOL TOTAL_FRUIT
  TOTAL_FRUIT = 33
</code>

=== List of operations ===
^ Operation ^ 
| ''+'' |
| ''-'' |
| ''*'' |
| ''/'' |

==== String operations ====

<code DCL>
$ APPLES = "Apples"
$ SHOW SYMBOL APPLES
  APPLES = "Apples"
$ FRUIT = "Oranges and " + APPLES
$ SHOW SYMBOL FRUIT
  FRUIT = "Oranges and Apples"
</code>

==== Using subshells in commands ====

Sub-shell is invoqued with ''2 SINGLE QUOTES+VARIABLE+1 SINGLE QUOTE'', for examples:
<code DCL>
$ FILETYPE = "login.com"
$ TYPEIT = "TYPE ''filename'"
$ SHOW SYMBOL TYPEIT
  "TYPE login.com"
</code>

<WRAP center round tip 60%>
Take care with string usage '':=''
</WRAP>
What works and what not (as a sub-shell):
  * Works:
<code DCL>
$ FILETYPE := "login.com"
$ TYPEIT := "TYPE ''filename'"
$ SHOW SYMBOL TYPEIT
  "TYPE login.com"
</code>

  * DON'T Work (as a literal)
<code DCL>
$ FILETYPE := "login.com"
$ TYPEIT := "TYPE" +  filename
$ SHOW SYMBOL TYPEIT
  "TYPE FILENAME"
</code>

<WRAP center round tip 60%>
In the other hand, without forcing string assignment
</WRAP>
Both are assigned as a variable:
<code DCL>
$ FILETYPE = "login.com"
$ TYPEIT = "TYPE ''filename'"
$ SHOW SYMBOL TYPEIT
  "TYPE login.com"
</code>
<code DCL>
$ FILETYPE = "login.com"
$ TYPEIT = "TYPE" +  filename
$ SHOW SYMBOL TYPEIT
  "TYPE login.com"
</code>

====== Startup ======
===== Show available boot devices =====
<code DCL>
show device
</code>
===== boot from device =====
<code DCL>
boot [DEVICE]
</code>
ex:
<code DCL>
boot DKA0
</code>

===== Login =====
**root** is ''SYSTEM'':
<code DCL>
 Welcome to OpenVMS (TM) Alpha Operating System, Version V8.3

Username: SYSTEM
Password:
</code>



===== Logout =====
<code DCL>
LOGOUT
</code>

<code DCL>
LOGOUT/FULL
</code>

====== Basic Commands ======

===== df =====
<code DCL>
SHOW DEVICE SYS$SYSDEVICE
</code>

===== See system parameters =====
To check the values of your system parameters, enter the following command:
<code DCL>
RUN SYS$SYSTEM:SYSGEN
</code>
And then under ''SYSGEN>'' prompt, you can list parameters, for example:
<code DCL>
SHOW WSMAX
</code>


===== Show system pagelets =====
<code DCL>
WRITE SYS$OUTPUT F$GETSYI("CONTIG_GBLPAGES")
</code>
===== Show free pagelets =====
<code DCL>
WRITE SYS$OUTPUT F$GETSYI("FREE_GBLSECTS")
</code>

===== Generate more pagelets =====
<code DCL>
AUTOGEN
</code>
===== Find how many pagelets are used by EXE =====
In this case ''DCLTABLES.EXE''
<code DCL>
DIRECTORY/SIZE SYS$LIBRARY:DCLTABLES.EXE
</code>


====== System config ======
===== change system config =====
You have to edit:
<code DCL>
SYS$SYSTEM:MODPARAMS.DAT
</code>
Still don't know how to edit...

===== update system parameters and reboot =====
<code DCL>
@SYS$UPDATE:AUTOGEN GETDATA REBOOT
</code>


===== Change dynamic parameters using SYSGEN=====
==== Run SYSGEN ====
<code DCL>RUN SYS$SYSTEM:SYSGEN
</code>
==== SYSGEN: Modify parameter ====
And (example):
<code DCL>
SYSGEN> USE ACTIVE
SYSGEN> SET GBLPAGES 100000
SYSGEN> WRITE ACTIVE
SYSGEN> EXIT
</code>


==== SYSGEN: List all parameters  ====
<code DCL>
SHOW /ALL
</code>


===== empty =====
<code DCL>
</code>