SE(1)SE(1)NAMEse - screen editor
SYNOPSISse [ --acdfghiklmstuvwxyz ] [ file ... ]
DESCRIPTION
Se is a screen oriented version of ed(1). It accepts the same commands
with a few differences.
Se must be run from a CRT terminal. It uses the termlib(3) terminal
operations library, which retrieves terminal capabilities from the
/etc/termcap database. For se to function, all of the following must
be true:
1. You must have the environment variable “TERM” set to the name of
your terminal type.
2. The /etc/termcap database must be accessible, and contain an
entry for your terminal; or the “TERMCAP” environment variable
must contain a description for your terminal. (See termlib(3)
for details.)
3. Your terminal must have the capability to do cursor motion.
Se first clears the screen, draws in its margins, and executes the com‐
mands in the file ./.serc, or failing that, $HOME/.serc, if either file
exists. It then processes the command line, obeying the options given
there, and begins reading your file (if you specified one). The .serc
file is only evaluated if the euid of se matches the owner for the file
and no other users have permission to write to the file. The screen it
draws looks something like this. (The parenthesized numerals are not
part of the screen layout, but are there to aid in the following dis‐
cussion.)
(1) (2) (3)
A |
B |#include <stdio.h>
C |
D *| register int i;
E |
. -> | for (i = 1; i <= 12; i++)
G | putc ('\n', stderr);
$ |
cmd> |_ (4)
11:39 myfile ........................ (5)
The display is divided into five parts: (1) the line number area, (2)
the mark name area, (3) the text area, (4) the command line, and (5)
the status line. The current line is indicated by the symbol “.” in
the line number area of the screen. In addition, a rocket (“->”) is
displayed to make the current line more obvious. The current mark name
of each line is shown in the markname area just to the left of the ver‐
tical bar. Other information, such as the number of lines read in, the
name of the file, and the time of day, are displayed in the status
line.
The cursor is positioned at the beginning of the command line, showing
you that se awaits your command. You may now enter any of the standard
ed commands and se will perform them, while making sure that the cur‐
rent line is always displayed on the screen.
You can set options to control the behavior of se on the command line,
simply by using a “-”, followed by the option letter, and any parame‐
ters that the option may take. These options can also be set after
invoking se with the options command, “o”, explained in detail in the
section on commands. Here is a summary:
opt = a | c | d[dir] | f | g | h | i[a | indent] |
k | l[lop] | lm[col] | m | s[filetype] |
t[tabs] | u[char] | v[col] | w[col] |
x | y[key] | z | -[lnr]
There are only a few other things that you need know to successfully
use se:
1. If you make an error, se automatically displays an error message
in the status line. It also leaves your command line intact so
that you may change it using in-line editing commands (see the
“v” command). If you don't want to bother with changing the
command, just hit DEL to erase the command.
2. The “p” command has a different meaning than in ed. When used
with line numbers, it displays as many of the lines in the spec‐
ified range as possible (always including the last line). When
used without line numbers, “p” displays the previous page.
3. The “:” command positions a specified line at the top of the
screen (e.g., “12:” positions the screen so that line 12 is at
the top). If no line number is specified, “:” displays the next
page.
Keeping these few differences in mind, you will see that se can perform
all of the functions of ed, while giving the advantage of a “window”
into the edit buffer.
Below is a summary of line number expressions, regular expressions and
commands. Where there is no difference between se and ed no explana‐
tion is given.
Line Number Expressions
n nth line.
. current line.
$ last line.
^ previous line.
- previous line.
capital letter A
Ath line on the screen. Se has a number of features that take
advantage of the window display to minimize keystrokes and speed
editing. In the line number area of the screen, se displays a
capital letter for each line, but in “absolute line number” mode
(controlled by the “oa” command; see the options command) se
displays the actual line number of each line.
# number of the first line on the screen.
/regular expression[/]
next line with pattern.
?regular expression[?]
previous line with pattern.
>name number of the next line having the given markname (search wraps
around, like //).
<name number of the previous line having the given markname (search
proceeds in reverse, like ??).
expression
any of the above operands may be combined with plus or minus
signs to produce a line number expression. Plus signs may be
omitted if desired (e.g., /parse/-5, /lexical/+2, /lexical/2,
$-5, .+6, .6). Unlike ed, se does not recognize trailing “+” or
“-” signs. They must always be followed by a integer. Succes‐
sive “+” or “-” signs (e.g. “--”) are also not allowed. How‐
ever, like vi(1), se will allow you to leave off the trailing
delimiter in forward searches, backward searches, in the substi‐
tute command, the join command, and in the transliteration com‐
mand.
Regular Expression Notation
^ beginning of line if first character in regular expression.
. any single character other than newline.
$ end of line if last character in regular expression.
[ccl] [^ccl]
character set.
* 0 or more matches of the preceding regular expression element.
\ ignore special meaning of the immediately following character
except “\(” and “\)”.
\(regular expression\)
Tags the text actually matched by the sub-pattern specified by
regular expression for use in the replacement part of a substi‐
tute command.
& Appearing in the replacement part of a substitute command, rep‐
resents the text actually matched by the pattern part of the
command.
% Appearing as the only character in the replacement part, repre‐
sents the replacement part used in the previous substitute com‐
mand. (This allows an empty replacement pattern as well.) If
there are other characters in the replacement part along with
the “%”, the “%” is left alone.
\digit Appearing in the replacement part of a substitute command, rep‐
resents the text actually matched by the tagged sub-pattern
specified by digit.
File names
Se will expand environment variables which appear anywhere in a path
name. Identifiers in a path name are treated as environment variables
if they start with a dollar sign “$”. A real “$” can be used if it is
escaped. If the named environment variable is not found, it is deleted
from the path name. The expanded path name will be placed in the sta‐
tus line.
The .serc File
When se starts up, it tries to open the file .serc in your current
directory. If that file cannot be found, it will attempt to open the
file .serc in your home directory. If either file exists, se will read
it, one line at a time, and execute each line as a command. If a line
has a “#” as the first character on the line, or if the line is empty,
the entire line is treated as a comment, otherwise it is executed.
Here is a sample .serc file:
# turn on tabs every 8 columns, auto indent
ot+8
oia
The .serc file is useful for setting up personalized options, without
having to type them on the command line every time, and without using a
special shell file in your bin (for sh(1)). The .serc file is only
evaluated if the euid of se matches the owner for the file and no other
users have permission to write to the file.
Command line options are processed after commands in the .serc file,
so, in effect, command line options can be used to over-ride the
defaults in your .serc file.
NOTE: Commands in the .serc file do not go through that part of se
which processes the special control characters (see below), so do not
use them in your .serc file.
Commands
(.)a[:text] Append
If the command is followed immediately by a colon, then whatever
text follows the colon is inserted without entering “append”
mode.
(.,.)c[:text] Change
If the command is followed immediately by a colon, then whatever
text follows the colon is inserted in place of the named lines
without entering “append” mode.
(.,.)d Delete
e[“!”|“x”] [filename] Enter
“e!”, enter now, is the same as “E” in ed. “ex” enters the file
with “XTABS” turned on, i.e. expand any tabs to blanks. File
names with extensions “s”, “c”, “h”, “f” and “r”, are automati‐
cally entered with “XTABS” turned on.
f [filename] File
(.,$)g/reg expr/command Global on pattern
none h[stuff] Help
This command provides access to on-line documentation on the
screen editor. “Stuff” may be used to select which information
is displayed.
(.)i[:text] Insert
If the command is immediately followed by a colon, then whatever
text follows is inserted without entering “append” mode. The
current line pointer is left at the last line inserted.
(^,.)j[/stuff[/]] Join
Join is basically the same in se and ed except if no line num‐
bers are specified, the default is to join the previous line
with the current line (as opposed to the current line and the
next line), and se allows you to indicate what is to replace the
newline(s) in “stuff”. The default is a single blank. If you
do specify “stuff”, the trailing delimiter is optional. “j/” is
considered the same as “j//”, i.e., the newline is deleted.
(.,.)k[m] marK
Se allows marks to be any single character other than a newline.
If “m” is not present, the lines are marked with the default
name of blank. (Ed allows only lower case letters to be marks.)
none l Locate
The Locate command places the system name into the status line
(e.g. “gatech” or “emory”). This is so that one can tell what
machine he is using from within the screen editor. This is par‐
ticularly useful for installations with many machines that can
run the editor, where the user can switch back and forth between
them, and become confused as to where he is at a given moment.
(.,.)mline
Move
(.,.)n[m] Name
If “m” is present, the last line in the specified range is
marked with it and all other lines having that mark name are
given the default mark name of blank. If “m” is not present,
the names of all lines in the range are cleared.
none o[stuff] Option
Editing options may be queried or set. “Stuff” determines which
options are affected. Options for se can be specified in three
ways; in the .serc file, on the command line that invokes se, or
with the “o” command. To specify an option with the “o” com‐
mand, just enter “o” followed immediately by the option letter
and its parameters. To specify an option on the command line,
just use “-” followed by the option letter and its parameters.
With this second method, if there are imbedded spaces in the
parameter list, the entire option should be enclosed in quotes.
For example, to specify the “a” (absolute line number) option
and tab stops at column 8 and every fourth thereafter with the
“o” command, just enter
oa
ot 8 +4
when se is waiting for a command. To enter the same options on
the invoking command line, you might use
se myfile -a "-t 8 +4"
You may also choose to put options that you will always want
into your .serc file. Commands in the .serc file should look
exactly the same as they would if they were typed at the se com‐
mand line. Command line options will always over-ride option
commands given in your .serc file.
The following summarizes the available se options:
a causes absolute line numbers to be displayed in the line
number area of the screen. The default behavior is to
display upper-case letters with the letter “A” corre‐
sponding to the first line in the window.
c inverts the case of all letters you type (i.e., converts
upper-case to lower-case and vice versa). This option
causes commands to be recognized only in upper-case and
alphabetic line numbers to be displayed and recognized
only in lower-case. In this mode, se displays the line
number letters in lower case and expects its command let‐
ters in upper case. Unshifted letters from the terminal
are converted to upper case and shifted letters to lower
case.
d[dir] selects the placement of the current line pointer follow‐
ing a “d” (delete) command. Dir must be either “>” or
“<”. If “>” is specified, the default behavior is
selected: the line following the deleted lines becomes
the new current line. If “<” is specified, the line
immediately preceding the deleted lines becomes the new
current line. If neither is specified, the current value
of dir is displayed in the status line.
f selects Fortran oriented options. This is equivalent to
specifying the “ot7 +3” option, and “XTABS” is turned on
(i.e. tabs are expanded).
g controls the behavior of the “s” (substitute) command
when it is under the control of a “g” (global) command.
Initially, if a substitute inside a global command fails,
se will not continue with the rest of the lines which
might succeed. If “og” is given, then the global substi‐
tute will continue, and lines which failed will not be
affected. Successive “og” commands will toggle this
behavior. An explanatory message is placed in the status
line.
h controls the use of hardware line insert/delete on termi‐
nals that have that capability. By default, line
insert/delete will be used if available. It is occasion‐
ally useful to turn this option off when using the editor
on a terminal which can't keep up, or if the communica‐
tions lines may be scrambling the control characters.
Each successive “oh” merely toggles a switch within the
editor. An explanatory message is placed in the status
line.
i[ a | indent ]
selects indent value for lines inserted with “a”, “c” and
“i” commands (initially 1). “a” selects auto-indent
which sets the indent to the value which equals the
indent of the previous line. If neither “a” nor indent
are specified, the current indent value is displayed in
the status line.
k indicates whether the current contents of your edit buf‐
fer have been saved or not by printing either a “saved”
or “not saved” message on your status line.
l[lop] sets the line number display option. Under control of
this option, se continuously displays the value of one of
three symbolic line numbers. lop may be “.”, “#”, or
“$”. If lop is omitted, the line number display is dis‐
abled.
lm[col]
sets the left margin to col which must be a positive
integer. This option will shift your entire screen to
the left, enabling you to see characters at the end of
the line that were previously off the screen; the charac‐
ters in columns 1 through col - 1 will not be visible.
You may continue editing in the normal fashion. To reset
your screen enter the command “olm 1”. If col is omit‐
ted, the current left margin column is displayed in the
status line.
m controls notification of the presence of existing mail
and/or the arrival of new mail in the user's mail file.
The mail file is taken from the “MAIL” variable in the
user's environment. On startup, if the mail file is not
empty, se will remark, “You have mail.” Then, if new
mail arrives, se will remark, “You have new mail,” and
ring the terminal's bell. The “m” option simply toggles
a notification switch, so that the user can turn off this
notification. The “om” command displays the current set‐
ting of the notify switch in the status line.
s[d | data | as | s | c | h | n | nr | nroff | p | r | f]
sets other options for case, tabs, etc., for data files,
“d” or “data”, assembly files, “as” or “s”, C files, “c”,
include files, “h”, nroff files, “n” or “nr” or “nroff”,
ratfor files, “r”, pascal files, “p”, and fortran files,
“f”. Options set for data and nroff files are “ow74” and
“ot+4”; for assembly files “ot 17+8” and “XTABS” is
turned on; for C, include, pascal and ratfor files
“ow74”, “ot+4” and “XTABS” is turned on; for fortran
files “ot 7+3” and “XTABS” is turned on. If “XTABS” is
turned on then tabs are expanded. If no argument is
specified the options effected by this command revert to
their default value.
t[tabs]
sets tab stops according to tabs. Tabs consists of a
series of numbers indicating columns in which tab stops
are to be set. If a number is preceded by a plus sign
(“+”), it indicates that the number is an increment;
stops are set at regular intervals separated by that many
columns, beginning with the most recently specified abso‐
lute column number. If no such number precedes the first
increment specification, the stops are set relative to
column 1. By default, tab stops are set in every third
column starting with column 1, corresponding to a tabs
specification of “+3”. If tabs is omitted, the current
tab spacing is displayed in the status line. Examples
ot 1 4 7 10 13 16 19 22 25 28 31 34 ...
ot +3
ot 7 +3
Once the tab stops are set, the control-i and control-e
keys can be used to move the cursor from its current
position forward or backward to the nearest stop, respec‐
tively.
u[chr] Normally, se displays a non-printing character (e.g. NEW‐
LINE, TAB ...) as a blank. With this option, you can
select the character that se displays in place of
unprintable characters. Chr may be any printable charac‐
ter. If chr is omitted, se displays the current replace‐
ment character on the status line. Non-printing charac‐
ters (such as se control characters), or any others for
that matter, may be entered by hitting the ESC key fol‐
lowed immediately by the key to generate the desired
character. Note, however, that the character you type is
taken literally, exactly as it is generated by your ter‐
minal, so case conversion does not apply.
v[col] sets the default “overlay column”. This is the column at
which the cursor is initially positioned by the “v” com‐
mand. Col must be a positive integer, or a dollar sign
($) to indicate the end of the line. If col is omitted,
the current overlay column is displayed in the status
line.
w[col] sets the “warning threshold” to col which must be a posi‐
tive integer. Whenever the cursor is positioned at or
beyond this column, the column number is displayed in the
status line and the terminal's bell is sounded. If col
is omitted, the current warning threshold is displayed in
the status line. The default warning threshold is 74,
corresponding to the first column beyond the right edge
of the screen on an 80 column crt.
x toggles tab compression and expansion (“XTABS”). If
XTABS is off, “ox” turns it on for subsequent “r”, and
“w”, commands. Be aware that the “e” command checks the
source option for files; use the “ex” command to force
tab expansion.
y[key] allows you to edit encrypted files. “oy” followed by a
key will cause the “e”, “r”, and “w” commands to encrypt
and decrypt files using crypt(1). “oy” by itself will
toggle the current encryption setting. If there is no
current key, se will ask you for one. Echoing is turned
off while you type your key in, and se asks you to type
it in twice, just to be sure. If encryption is turned
on, and you type a plain “oy”, it will be turned off.
Note that doing so causes se to forget the value of the
encryption key. Encryption in indicated by the message
“ENCRYPT” in the status line. The key is never shown on
your screen.
z suspends the editor (puts it in the background) and
returns to the user's shell. (It has to be a shell that
understands Berkeley job control, or else you'll be in
trouble.) The editor will warn you if the edit buffer
has not been saved. This is the only way to suspend the
editor; the editor uses control-z for its own purposes
(see the section on control characters, below). If you
normally run /bin/sh without job control, this command
has no effect at all.
On UNIX systems without the Berkeley job control mecha‐
nism, this option will be recognized, but will have no
effect. Instead, an explanatory message will be placed
in the status line.
-[lnr] splits the screen at the line specified by lnr which must
be a simple line number within the current window. All
lines above lnr remain frozen on the screen, the line
specified by lnr is replaced by a row of dashes, and the
space below this row becomes the new window on the file.
Further editing commands do not affect the lines dis‐
played in the top part of the screen. If lnr is omitted,
the screen is restored to its full size.
(.,.)p Print
Prints all the lines in the given range. As much as possible of
the range is displayed, always including the last line; if no
range is given, the previous page is displayed. The current
line pointer is left at the last line printed.
q[!] Quit
“q!”, exit immediately, is the same as “Q” in ed.
(.)r[x] [filename] Read
If no line number is specified, the named file is read starting
after current line (as opposed to ed where the file is read at
the end of the edit buffer). “rx” causes tabs to be expanded in
the lines read.
(.,.)s[/reg expr/sub[/][g][p]] Substitute
If no pattern and replacement are specified after the “s”, se
will behave as if you had typed “s//%/”, i.e. for the saved
search pattern, substitute the saved replacement pattern. To
just delete a pattern, you may type “s/stuff”, and se will
behave as if you had typed “s/stuff//”.
(.,.)t<n> Copy
(“To” is the ed mnemonic).
u[d] Undo
“u” undoes the effects of the previous command, on the last line
affected (for instance a substitute command). “ud” undoes the
last delete, i.e. it inserts the last deleted line after the
current line. Se does not have a global undo capability.
(.,.)v oVerlay — screen oriented editing
Full screen editing with se is accomplished through the use of
control characters for editing functions. With screen oriented
editing, control characters may be used to modify text anywhere
in the buffer. A control-v may be used to quit overlay mode. A
control-f may be used to restore the current line to its origi‐
nal state and terminate the command. Since se supports such a
large number of control functions, the mnemonic value of control
character assignments has dwindled to almost zero. About the
only thing mnemonic is that most symmetric functions have been
assigned to opposing keys on the keyboard (e.g., forward and
backward tab to control-i and control-e, forward and backward
space to control-g and control-h, skip right and left to con‐
trol-o and control-w, and so on). We feel pangs of conscience
about this, but can find no more satisfactory alternative. If
you feel the control character assignments are terrible and you
can find a better way, you may change them by modifying the def‐
initions in se and recompiling.
Except for a few special purpose ones, control characters can be
used anywhere, even on the command line. (This is why erroneous
commands are not erased — you may want to edit them.) Most of
the functions work on a single line, but the cursor may be posi‐
tioned anywhere in the buffer. Refer to the next section which
describes each control character in detail.
(1,$)w[+ | > | !] [filename] Write
Write the portion of the buffer specified to the named file. If
“+” or “>” is given, the portion of the buffer is appended to
the file; otherwise the portion of the buffer replaces the file.
“w!”, write immediately, is the same as “W” in ed.
(1,$)x/reg expr/command eXclude on pattern
(.,.)y[/from/to[/][p]] TranslYterate (sic)
The range of characters specified by “from” is transliterated
into the range of characters specified by “to”. The last line on
which something was transliterated is printed if the “p” option
is used. The last line in the range becomes the new current
line. As with the substitute and join commands, and pattern
searches, the trailing delimiter is optional. Se saves both the
“from” and “to” parts of the transliterate command: “y” is the
same as “y//%/”, i.e. transliterate the saved “from” range into
the saved “to” range. The “%” is special only if it is the only
character in the “to” part of the command.
(.,.)zbleft[,right][char]DrawBox
A box is drawn on the given lines, in the given columns, using
the given char. This command can be used as an aid for prepar‐
ing block diagrams, flowcharts, or tables.
Line numbers are used to specify top and bottom row positions of
the box. Left and right specify left and right column positions
of the box. If second line number is omitted, the box degener‐
ates to a horizontal line. If right-hand column is omitted, the
box degenerates to a vertical line. If char is omitted, it
defaults to blank, allowing erasure of a previously-drawn box.
For example, “1,10zb15,25*” would draw a box 10 lines high and
11 columns across, using asterisks. The upper left corner of
the box would be on line 1, column 15, and the lower right cor‐
ner on line 10, column 25.
(.)= Equals what line number?
(1,$)~mcommand global exclude on markname
Similar to the “x” prefix except that “command” is performed for
all lines in the range that do not have the mark name “m”.
(1,$)'mcommand global on markname
Similar to the “g” prefix except that “command” is performed for
all lines in the range that have the mark name “m”.
(.): display next page
The next page of the buffer is displayed and the current line
pointer is placed at the top of the window.
none ![UNIX command] escape to the shell
The user's choice of shell is taken from the “SHELL” environment
variable (if it exists), and is used to execute UNIX command if
it is present. Otherwise, an interactive shell is created.
After an interactive shell exits, the screen is immediately
redrawn. If a command was run, the results are left on the
screen, and the user must type RETURN to redraw the editing win‐
dow. This is how vi(1) behaves. If the first character of the
UNIX command is a `!', then the `!' is replaced with the text of
the previous shell command. An unescaped `%' in the UNIX com‐
mand will be replaced with the current saved file name. If the
shell command is expanded, se will echo it first, and then exe‐
cute it. This behavior is identical to the version of ed in
UNIX System V.
Control Characters
The set of control characters defined below can be used for correcting
mistakes while typing regular editing commands, for correcting commands
that have caused an error message to be displayed, for correcting lines
typed in append mode, or for in-line editing using the “v” command.
control-a
Toggle insert mode. The status of the insertion indicator is
inverted. Insert mode, when enabled, causes the characters you
type to be inserted at the current cursor position in the line
instead of overwriting the characters that were there previ‐
ously. When insert mode is in effect, “INSERT” appears in the
status line.
control-b
Scan right and erase. The current line is scanned from the cur‐
rent cursor position to the right margin until an occurrence of
the next character typed is found. When the character is found,
all characters from the current cursor position up to (but not
including) the scanned character are deleted and the remainder
of the line is moved to the left to close the gap. The cursor
is left in the same column which is now occupied by the scanned
character. If the line to the right of the cursor does not con‐
tain the character being sought, the terminal's bell is sounded.
Se remembers the last character that was scanned using this or
any of the other scanning keys; if control-b is hit twice in a
row, this remembered character is used instead of a literal con‐
trol-b.
control-c
Insert blank. The characters at and to the right of the current
cursor position are moved to the right one column and a blank is
inserted to fill the gap.
control-d
Cursor up. The effect of this key depends on se's current mode.
When in command mode, the current line pointer is moved to the
previous line without affecting the contents of the command
line. If the current line pointer is at line 1, the last line
in the file becomes the new current line. In overlay mode (viz.
the “v” command), the cursor is moved up one line while remain‐
ing in the same column. In append mode, this key is ignored.
control-e
Tab left. The cursor is moved to the nearest tab stop to the
left of its current position.
control-f
“Funny” return. The effect of this key depends on the editor's
current mode. In command mode, the current command line is
entered as-is, but is not erased upon completion of the command;
in append mode, the current line is duplicated; in overlay mode
(viz. the “v” command), the current line is restored to its
original state and command mode is reentered (except if under
control of a global prefix).
control-g
Cursor right. The cursor is moved one column to the right.
control-h
Cursor left. The cursor is moved one column to the left. Note
that this does not erase any characters; it simply moves the
cursor.
control-i
Tab right. The cursor is moved to the next tab stop to the
right of its current position. Again, no characters are erased.
control-k
Cursor down. As with the control-d key, this key's effect
depends on the current editing mode. In command mode, the cur‐
rent line pointer is moved to the next line without changing the
contents of the command line. If the current line pointer is at
the last line in the file, line 1 becomes the new current line.
In overlay mode (viz. the “v” command), the cursor is moved down
one line while remaining in the same column. In append mode,
control-k has no effect.
control-l
Scan left. The cursor is positioned according to the character
typed immediately after the control-l. In effect, the current
line is scanned, starting from the current cursor position and
moving left, for the first occurrence of this character. If
none is found before the beginning of the line is reached, the
scan resumes with the last character in the line. If the line
does not contain the character being looked for, the message
“NOT FOUND” is printed in the status line. Se remembers the
last character that was scanned for using this key; if the con‐
trol-l is hit twice in a row, this remembered character is
searched for instead of a literal control-l. Apart from this,
however, the character typed after control-l is taken literally,
so se's case conversion feature does not apply.
control-m
Kill right and terminate; identical to the NEWLINE key described
below.
control-n
Scan left and erase. The current line is scanned from the cur‐
rent cursor position to the left margin until an occurrence of
the next character typed is found. Then that character and all
characters to its right up to (but not including) the character
under the cursor are erased. The remainder of the line, as well
as the cursor are moved to the left to close the gap. If the
line to the left of the cursor does not contain the character
being sought, the terminal's bell is sounded. If control-n is
hit twice in a row, the last character scanned for is used
instead of a literal control-n.
control-o
Skip right. The cursor is moved to the first position beyond
the current end of line.
control-p
Interrupt. If executing any command except “a”, “c”, “i” or
“v”, se aborts the command and reenters command mode. The com‐
mand line is not erased. This is the only way to interrupt the
editor. Se ignores the SIGQUIT signal (see signal(2)); in fact
it disables generating quits from the terminal. The editor uses
ASCII FS (control-\) for its own purposes, and changes the ter‐
minal driver to make control-p be the interrupt character.
control-]
Fix screen. The screen is reconstructed from se's internal rep‐
resentation of the screen.
control-r
Erase right. The character at the current cursor position is
erased and all characters to its right are moved left one posi‐
tion.
control-j
Scan right. This key is identical to the control-l key
described above, except that the scan proceeds to the right from
the current cursor position.
control-t
Kill right. The character at the current cursor position and
all those to its right are erased.
control-u
Erase left. The character to the left of the current cursor
position is deleted and all characters to its right are moved to
the left to fill the gap. The cursor is also moved left one
column, leaving it over the same character.
control-v
Skip right and terminate. The cursor is moved to the current end
of line and the line is terminated.
control-w
Skip left. The cursor is positioned at column 1.
control-x
Insert tab. The character under the cursor is moved right to
the next tab stop; the gap is filled with blanks. The cursor is
not moved.
control-y
Kill left. All characters to the left of the cursor are erased;
those at and to the right of the cursor are moved to the left to
fill the void. The cursor is left in column 1.
control-z
Toggle case conversion mode. The status of the case conversion
indicator is inverted; if case inversion was on, it is turned
off, and vice versa. Case inversion, when in effect, causes all
upper case letters to be converted to lower case, and all lower
case letters to be converted to upper case (just like the alpha-
lock key on some terminals). You can type control-z at any time
to toggle the case conversion mode. When case inversion is in
effect, se displays the word “CASE” in the status line. Note
that se continues to recognize alphabetic line numbers in upper
case only, in contrast to the “case inversion” option (see the
description of options under the option command).
control-_ (US)
Insert newline. A newline character is inserted before the cur‐
rent cursor position, and the cursor is moved one position to
the right. The newline is displayed according to the current
non-printing replacement character (see the “u” option).
control-\ (FS)
Tab left and erase. Characters are erased starting with the
character at the nearest tab stop to the left of the cursor up
to but not including the character under the cursor. The rest
of the line, including the cursor, is moved to the left to close
the gap.
Use control-p to interrupt the editor.
control-^ (control-~, RS)
Tab right and erase. Characters are erased starting with the
character under the cursor up to but not including the character
at the nearest tab stop to the right of the cursor. The rest of
the line is then shifted to the left to close the gap.
NEWLINE
Kill right and terminate. The characters at and to the right of
the current cursor position are deleted, and the line is termi‐
nated.
DEL Kill all. The entire line is erased, along with any error mes‐
sage that appears in the status line.
ESC Escape. The ESC key provides a means for entering se's control
characters literally as text into the file. In fact, any char‐
acter that can be generated from the keyboard is taken literally
when it immediately follows the ESC key. If the character is
non-printing (as are all of se's control characters), it appears
on the screen as the current non-printing replacement character
(normally a blank — see the options command “ou”).
Windowing Systems
On 4.3 BSD, and on the AT&T Unix/PC or 3B1, se notices when its current
window changes size or is repositioned, and adjusts the screen image
accordingly.
FILES
$HOME/.serc
se initialization file.
/usr/tmp/process id.sequence_number
for scratch file.
./se.hangup
where se dumps its buffer if it catches a hang-up signal.
/usr/local/lib/se_h/*
help scripts for the “h” command.
DIAGNOSTICS
Self explanatory diagnostics appear in the status line.
CAVEATS
Se will never dump its buffer into an encrypted file when it encounters
a hang-up, even if encryption was turned on at the time.
SEE ALSO
Software Tools, Software Tools in Pascal, Software Tools Subsystem
User's Guide, ed(1), crypt(1), ksh(1), scriptse(1), sh(1), vi(1), sig‐
nal(2), termlib(3), termio(7), environ(5), termcap(5)BUGS
Can only be run from a script if the script is first passed through
scriptse(1).
Tabs could be handled better. This is because se was originally writ‐
ten for Prime computers.
Does not check whether or not it has been put into the background (this
is to allow se to be used with the USENET news software, which does a
poor job of signal handling for child processes).
Occasionally flakes out the screen when doing line inserts and deletes,
due to problems within the termlib(3) package in putting out the right
number of padding characters. Type a control-] to redraw the screen.
The auto-indent feature does not recognize a line consisting of just
blanks and then a “.” to terminate input, when the “.” is not in the
same position as the first non-blank character of the previous line.
There is no global undo capability.
The help screens could use a rewrite.
AUTHORS
Se started out as the version of ed that came with the book “Software
Tools,” by Kernighan and Plauger, which was written in Ratfor. On the
Pr1me computers at the School of Information and Computer Science at
Georgia Tech, Dan Forsyth, Perry Flinn, and Alan Akin added all the
enhancements suggested in the exercises in the book, and some more of
their own. Jack Waugh made extensive modifications to turn the line
editor into a screen editor; further work was done by Dan Forsyth. All
of this was in an improved Georgia Tech version of Ratfor.
Later, Dan Forsyth, then at Medical Systems Development Corporation,
converted the Ratfor version into C, for Berkeley Unix (4.1 BSD). At
Georgia Tech, Arnold Robbins took the C version and added many new fea‐
tures and improvements, the most important of which was termlib support
and System V support. The existing help screens were edited and com‐
pleted at that time, as well. This was finished in early 1985.
In early 2013, Thomas Cort continued maintenance of se, modernizing the
code base and build system to support current POSIX operating systems.
Thomas' primary motivation is to preserve this bit of computing his‐
tory. His goals are to squash any remaining bugs and make se as porta‐
ble as possible. No major new features will be added. He can be reached
at tcort@se-editor.org
local SE(1)
