====== Survival TECO ======

Version 3.0

Learning to speak a little TECO can be really useful to edit files on old DEC and related systems.

===== Rules =====

  - Pressing the Escape key (displayed in TECO and shown below as **$** — that's //not// a dollar key) twice executes typed commands instead of the more familiar Enter key. (A single **$** terminates string arguments for some commands.)
  - Commands don't have to be executed one-at-a-time. You can type a long series of commands then **$ $** and TECO will execute the commands in order.
  - TECO is character-oriented, so it remembers the character position of your current location in the file, called "pointer". Most commands display or change the file's contents at pointer, or move pointer to another location in the file.

===== Commands =====

| 1. | ''ER''//file//**$**''Y''<sup>1</sup> | Open file for input and read | 9. | ''J'' | Jump to beginning of file |
| 2. | ''EW''//file//**$**<sup>1</sup> | Open file for output | 10. | ''ZJ'' | Jump to end of file |
| 3. | ''EX'' | Save and exit | 11. | ''T''<sup>3</sup> | Type from pointer to end of line |
| 4. | ''^C ^C'' | Exit (no save) | 12. | ''V'' | Type current line |
| 5. | ''C''<sup>2</sup> | Move character forward | 13. | ''D''<sup>2</sup> | Delete character at pointer |
| 6. | ''R''<sup>2</sup> | Move character backward | 14. | ''K''<sup>3</sup> | Delete current line |
| 7. | ''L''<sup>3</sup> | Move to beginning of next line | 15. | ''S''//text//**$** | Search for //text// | 
| 8. | ''I''//text//**$** | Insert //text// | 16. | ''FS''//text1//**$**//text2//**$** | Substitute //text2// for //text1// | 

==== Notes ====

  - Some versions of TECO accept a file name as a command line argument, making ''ER''... and ''EW''... unnecessary. Some versions of TECO have a command ''EB''//file//**$**''Y'' that does the same as ''ER''... ''EW''... in one step. 
  - Numeric prefix (''C'', ''R'', ''D''): move/delete multiple characters (negative reverses direction) 
  - Numeric prefix (''L'', ''T'', ''K''): move/type/delete multiple lines (negative reverses direction); (''T'', ''K'' only) prefix ''H'': type/delete whole file 

===== Availability =====

You can use TECO on the following LCM+L systems.

| dec-10 | DECSYSTEM-2065 | Invoke TECO with ''MAKE'' to create a new file or ''TECO'' to edit an old file. |
| ki587 | DECsystem-1090 | ::: |
| toad2a | TOAD-2 | ::: |
| vax780 | VAX-11/785 | ''EDIT/TECO'' to create or edit a file with TECO. |



===== References =====

  * Golden, V. Ellen. [[https://web.archive.org/web/20120419073729/http://www.avanthar.com/~healyzh/_info_/its.primer|An Introduction to ITS for the MACSYMA User]]. Massachusetts Institute of Technology Laboratory for Computer Science Mathlab Group. 14 April 1981. Accessed 16 Nov. 2017.
  * [[https://web.archive.org/web/20120402215507/http://www.avanthar.com/~healyzh/teco/TecoPocketGuide.html|TECO Pocket Guide]]. Digital Equipment Corporation. 1978. Accessed 16 Nov. 2017.

//"You can hack anything you want with TECO ..."// — [[https://www.hactrn.net/sra/|sra]]. [[https://www.hactrn.net/sra/alice/alices.pdp10|Alice's PDP-10]]

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//This page is based on [[http://sdf.org/?tutorials/survival-teco-2.0|Survival TECO Version 2.0]] at [[http://sdf.org|SDF]].//