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<head>
<title>sam(1) - Plan 9 from User Space</title>
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<tr><td width=20><td>
<tr><td width=20><td><b>SAM(1)</b><td align=right><b>SAM(1)</b>
<tr><td width=20><td colspan=2>
<br>
<p><font size=+1><b>NAME </b></font><br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
sam, B, E, sam.save, samterm, samsave – screen editor with structural
regular expressions<br>
</table>
<p><font size=+1><b>SYNOPSIS </b></font><br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<tt><font size=+1>sam</font></tt> [ <i>option ...</i> ] [ <i>files</i> ]
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
<tt><font size=+1>sam −r</font></tt> <i>machine
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</i>
<tt><font size=+1>sam.save
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>B</font></tt> <i>file</i>[<tt><font size=+1>:</font></tt><i>line</i>] ...
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
<tt><font size=+1>E</font></tt> <i>file<br>
</i>
</table>
<p><font size=+1><b>DESCRIPTION </b></font><br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<i>Sam</i> is a multi-file editor. It modifies a local copy of an external
file. The copy is here called a <i>file</i>. The files are listed in
a menu available through mouse button 3 or the <tt><font size=+1>n</font></tt> command. Each
file has an associated name, usually the name of the external
file from which it was read, and a ‘modified’ bit that indicates
whether the editor’s file agrees with the external file. The external
file is not read into the editor’s file until it first becomes
the current file--that to which editing commands apply--whereupon
its menu entry is printed. The options are<br>
<tt><font size=+1>−d</font></tt> Do not ‘download’ the terminal part of <i>sam</i>. Editing will be
done with the command language only, as in <a href="../man1/ed.html"><i>ed</i>(1)</a>.<br>
<tt><font size=+1>−r</font></tt> <i>machine</i> Run the host part remotely on the specified machine,
the terminal part locally.<br>
<tt><font size=+1>−s</font></tt> <i>path</i> Start the host part from the specified file on the remote
host. Only meaningful with the <tt><font size=+1>−r</font></tt> option.<br>
<tt><font size=+1>−t</font></tt> <i>path</i> Start the terminal part from the specified file. Useful
for debugging.<br>
<p><font size=+1><b>Regular expressions </b></font><br>
Regular expressions are as in <a href="../man7/regexp.html"><i>regexp</i>(7)</a> with the addition of <tt><font size=+1>\n</font></tt>
to represent newlines. A regular expression may never contain
a literal newline character. The empty regular expression stands
for the last complete expression encountered. A regular expression
in <i>sam</i> matches the longest leftmost substring formally
matched by the expression. Searching in the reverse direction
is equivalent to searching backwards with the catenation operations
reversed in the expression.<br>
<p><font size=+1><b>Addresses </b></font><br>
An address identifies a substring in a file. In the following,
‘character <i>n</i>’ means the null string after the <i>n</i>-th character in
the file, with 1 the first character in the file. ‘Line <i>n</i>’ means
the <i>n</i>-th match, starting at the beginning of the file, of the
regular expression <tt><font size=+1>.*\n?</font></tt>. All files always have a current substring,
called
dot, that is the default address.<br>
<p><font size=+1><b>Simple Addresses </b></font><br>
<tt><font size=+1>#</font></tt><i>n</i> The empty string after character <i>n</i>; <tt><font size=+1>#0</font></tt> is the beginning of the
file.<br>
<i>n</i> Line <i>n</i>; <tt><font size=+1>0</font></tt> is the beginning of the file.<br>
<tt><font size=+1>/</font></tt><i>regexp</i><tt><font size=+1>/<br>
?</font></tt><i>regexp</i><tt><font size=+1>?<br>
</font></tt>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
The substring that matches the regular expression, found by looking
toward the end (<tt><font size=+1>/</font></tt>) or beginning (<tt><font size=+1>?</font></tt>) of the file, and if necessary
continuing the search from the other end to the starting point
of the search. The matched substring may straddle the starting
point. When entering a pattern containing a literal
question mark for a backward search, the question mark should
be specified as a member of a class.<br>
</table>
<tt><font size=+1>0</font></tt> The string before the first full line. This is not necessarily
the null string; see <tt><font size=+1>+</font></tt> and <tt><font size=+1>−</font></tt> below.<br>
<tt><font size=+1>$</font></tt> The null string at the end of the file.<br>
<tt><font size=+1>.</font></tt> Dot.<br>
<tt><font size=+1>'</font></tt> The mark in the file (see the <tt><font size=+1>k</font></tt> command below).<br>
"<i>regexp</i>"<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
Preceding a simple address (default <tt><font size=+1>.</font></tt>), refers to the address
evaluated in the unique file whose menu line matches the regular
expression.<br>
</table>
<p><font size=+1><b>Compound Addresses </b></font><br>
In the following, <i>a1</i> and <i>a2</i> are addresses.<br>
<i>a1</i><tt><font size=+1>+</font></tt><i>a2</i> The address <i>a2</i> evaluated starting at the end of <i>a1</i>.<br>
<i>a1</i><tt><font size=+1>−</font></tt><i>a2</i> The address <i>a2</i> evaluated looking in the reverse direction
starting at the beginning of <i>a1</i>.<br>
<i>a1</i><tt><font size=+1>,</font></tt><i>a2</i> The substring from the beginning of <i>a1</i> to the end of <i>a2</i>.
If <i>a1</i> is missing, <tt><font size=+1>0</font></tt> is substituted. If <i>a2</i> is missing, <tt><font size=+1>$</font></tt> is substituted.<br>
<i>a1</i><tt><font size=+1>;</font></tt><i>a2</i> Like <i>a1</i><tt><font size=+1>,</font></tt><i>a2</i>, but with <i>a2</i> evaluated at the end of, and dot
set to, <i>a1</i>.
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
The operators <tt><font size=+1>+</font></tt> and <tt><font size=+1>−</font></tt> are high precedence, while <tt><font size=+1>,</font></tt> and <tt><font size=+1>;</font></tt> are low
precedence.
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
In both <tt><font size=+1>+</font></tt> and <tt><font size=+1>−</font></tt> forms, if <i>a2</i> is a line or character address with
a missing number, the number defaults to 1. If <i>a1</i> is missing,
<tt><font size=+1>.</font></tt> is substituted. If both <i>a1</i> and <i>a2</i> are present and distinguishable,
<tt><font size=+1>+</font></tt> may be elided. <i>a2</i> may be a regular expression; if it is delimited
by <tt><font size=+1>?</font></tt>’s, the effect of the <tt><font size=+1>+</font></tt> or <tt><font size=+1>−</font></tt> is reversed.
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
It is an error for a compound address to represent a malformed
substring. Some useful idioms: <i>a1</i><tt><font size=+1>+−</font></tt> (<i>a1</i>-+) selects the line containing
the end (beginning) of a1. <tt><font size=+1>0/</font></tt><i>regexp</i><tt><font size=+1>/</font></tt> locates the first match of
the expression in the file. (The form <tt><font size=+1>0;//</font></tt> sets dot unnecessarily.)
<tt><font size=+1>./</font></tt><i>regexp</i><tt><font size=+1>///</font></tt> finds the second following
occurrence of the expression, and <tt><font size=+1>.,/</font></tt><i>regexp</i><tt><font size=+1>/</font></tt> extends dot.<br>
<p><font size=+1><b>Commands </b></font><br>
In the following, text demarcated by slashes represents text delimited
by any printable character except alphanumerics. Any number of
trailing delimiters may be elided, with multiple elisions then
representing null strings, but the first delimiter must always
be present. In any delimited text, newline may not appear
literally; <tt><font size=+1>\n</font></tt> may be typed for newline; and <tt><font size=+1>\/</font></tt> quotes the delimiter,
here <tt><font size=+1>/</font></tt>. Backslash is otherwise interpreted literally, except in
<tt><font size=+1>s</font></tt> commands.
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
Most commands may be prefixed by an address to indicate their
range of operation. Those that may not are marked with a <tt><font size=+1>*</font></tt> below.
If a command takes an address and none is supplied, dot is used.
The sole exception is the <tt><font size=+1>w</font></tt> command, which defaults to <tt><font size=+1>0,$</font></tt>. In
the description, ‘range’ is used to represent whatever
address is supplied. Many commands set the value of dot as a side
effect. If so, it is always set to the ‘result’ of the change:
the empty string for a deletion, the new text for an insertion,
etc. (but see the <tt><font size=+1>s</font></tt> and <tt><font size=+1>e</font></tt> commands).<br>
<p><font size=+1><b>Text commands </b></font><br>
<tt><font size=+1>a/</font></tt><i>text</i><tt><font size=+1>/<br>
</font></tt>or<br>
<tt><font size=+1>a<br>
</font></tt><i>lines of text<br>
</i><tt><font size=+1>.</font></tt> Insert the text into the file after the range. Set dot.<br>
<tt><font size=+1>c<br>
i</font></tt> Same as <tt><font size=+1>a</font></tt>, but <tt><font size=+1>c</font></tt> replaces the text, while <tt><font size=+1>i</font></tt> inserts <i>before</i> the
range.<br>
<tt><font size=+1>d</font></tt> Delete the text in the range. Set dot.<br>
<tt><font size=+1>s/</font></tt><i>regexp</i><tt><font size=+1>/</font></tt><i>text</i><tt><font size=+1>/<br>
</font></tt>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
Substitute <i>text</i> for the first match to the regular expression
in the range. Set dot to the modified range. In <i>text</i> the character
<tt><font size=+1>&</font></tt> stands for the string that matched the expression. Backslash
behaves as usual unless followed by a digit: <tt><font size=+1>\</font></tt><i>d</i> stands for the
string that matched the subexpression begun by the <i>d</i>-th left
parenthesis. If <i>s</i> is followed immediately by a number <i>n</i>, as in
<tt><font size=+1>s2/x/y/</font></tt>, the <i>n</i>-th match in the range is substituted. If the command
is followed by a <tt><font size=+1>g</font></tt>, as in <tt><font size=+1>s/x/y/g</font></tt>, all matches in the range are
substituted.<br>
</table>
<tt><font size=+1>m</font></tt> <i>a1<br>
</i><tt><font size=+1>t</font></tt> <i>a1</i> Move (<tt><font size=+1>m</font></tt>) or copy (<tt><font size=+1>t</font></tt>) the range to after <i>a1</i>. Set dot.<br>
<p><font size=+1><b>Display commands </b></font><br>
<tt><font size=+1>p</font></tt> Print the text in the range. Set dot.<br>
<tt><font size=+1>=</font></tt> Print the line address and character address of the range.<br>
<tt><font size=+1>=#</font></tt> Print just the character address of the range.<br>
<p><font size=+1><b>File commands </b></font><br>
* <tt><font size=+1>b</font></tt> <i>file-list<br>
</i>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
Set the current file to the first file named in the list that
<i>sam</i> also has in its menu. The list may be expressed <tt><font size=+1><</font></tt><i>Plan 9 command</i>
in which case the file names are taken as words (in the shell
sense) generated by the Plan 9 command.<br>
</table>
* <tt><font size=+1>B</font></tt> <i>file-list<br>
</i>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
Same as <tt><font size=+1>b</font></tt>, except that file names not in the menu are entered
there, and all file names in the list are examined.<br>
</table>
* <tt><font size=+1>n</font></tt> Print a menu of files. The format is:<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<tt><font size=+1>'</font></tt> or blankindicating the file is modified or clean,<br>
<tt><font size=+1>−</font></tt> or <tt><font size=+1>+</font></tt> indicating the file is unread or has been read (in the terminal,
<tt><font size=+1>*</font></tt> means more than one window is open),<br>
<tt><font size=+1>.</font></tt> or blankindicating the current file,<br>
a blank,<br>
and the file name.<br>
</table>
* <tt><font size=+1>D</font></tt> <i>file-list<br>
</i>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
Delete the named files from the menu. If no files are named, the
current file is deleted. It is an error to <tt><font size=+1>D</font></tt> a modified file,
but a subsequent <tt><font size=+1>D</font></tt> will delete such a file.<br>
</table>
<p><font size=+1><b>I/O Commands </b></font><br>
* <tt><font size=+1>e</font></tt> <i>filename<br>
</i>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
Replace the file by the contents of the named external file. Set
dot to the beginning of the file.<br>
</table>
<tt><font size=+1>r</font></tt> <i>filename<br>
</i>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
Replace the text in the range by the contents of the named external
file. Set dot.<br>
</table>
<tt><font size=+1>w</font></tt> <i>filename<br>
</i>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
Write the range (default <tt><font size=+1>0,$</font></tt>) to the named external file.<br>
</table>
* <tt><font size=+1>f</font></tt> <i>filename<br>
</i>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
Set the file name and print the resulting menu entry.
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</table>
If the file name is absent from any of these, the current file
name is used. <tt><font size=+1>e</font></tt> always sets the file name; <tt><font size=+1>r</font></tt> and <tt><font size=+1>w</font></tt> do so if the
file has no name.<br>
<tt><font size=+1><</font></tt> <i>Plan 9-command<br>
</i>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
Replace the range by the standard output of the Plan 9 command.<br>
</table>
<tt><font size=+1>></font></tt> <i>Plan 9-command<br>
</i>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
Send the range to the standard input of the Plan 9 command.<br>
</table>
<tt><font size=+1>|</font></tt> <i>Plan 9-command<br>
</i>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
Send the range to the standard input, and replace it by the standard
output, of the Plan 9 command.<br>
</table>
* <tt><font size=+1>!</font></tt> <i>Plan 9-command<br>
</i>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
Run the Plan 9 command.<br>
</table>
* <tt><font size=+1>cd</font></tt> <i>directory<br>
</i>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
Change working directory. If no directory is specified, <tt><font size=+1>$home</font></tt>
is used.
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</table>
In any of <tt><font size=+1><</font></tt>, <tt><font size=+1>></font></tt>, <tt><font size=+1>|</font></tt> or <tt><font size=+1>!</font></tt>, if the <i>Plan 9 command</i> is omitted the last
<i>Plan 9 command</i> (of any type) is substituted. If <i>sam</i> is <i>downloaded</i>
(using the mouse and raster display, i.e. not using option <tt><font size=+1>−d</font></tt>),
<tt><font size=+1>!</font></tt> sets standard input to <tt><font size=+1>/dev/null</font></tt>, and otherwise unassigned output
(<tt><font size=+1>stdout</font></tt> for <tt><font size=+1>!</font></tt> and <tt><font size=+1>></font></tt>, <tt><font size=+1>stderr</font></tt> for all) is placed in
<tt><font size=+1>/tmp/sam.err</font></tt> and the first few lines are printed.<br>
<p><font size=+1><b>Loops and Conditionals </b></font><br>
<tt><font size=+1>x/</font></tt><i>regexp</i><tt><font size=+1>/</font></tt> <i>command<br>
</i>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
For each match of the regular expression in the range, run the
command with dot set to the match. Set dot to the last match.
If the regular expression and its slashes are omitted, <tt><font size=+1>/.*\n/</font></tt>
is assumed. Null string matches potentially occur before every
character of the range and at the end of the range.
</table>
<tt><font size=+1>y/</font></tt><i>regexp</i><tt><font size=+1>/</font></tt> <i>command<br>
</i>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
Like <tt><font size=+1>x</font></tt>, but run the command for each substring that lies before,
between, or after the matches that would be generated by <tt><font size=+1>x</font></tt>. There
is no default regular expression. Null substrings potentially
occur before every character in the range.<br>
</table>
* <tt><font size=+1>X/</font></tt><i>regexp</i><tt><font size=+1>/</font></tt> <i>command<br>
</i>
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For each file whose menu entry matches the regular expression,
make that the current file and run the command. If the expression
is omitted, the command is run in every file.<br>
</table>
* <tt><font size=+1>Y/</font></tt><i>regexp</i><tt><font size=+1>/</font></tt> <i>command<br>
</i>
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Same as <tt><font size=+1>X</font></tt>, but for files that do not match the regular expression,
and the expression is required.<br>
</table>
<tt><font size=+1>g/</font></tt><i>regexp</i><tt><font size=+1>/</font></tt> <i>command<br>
</i><tt><font size=+1>v/</font></tt><i>regexp</i><tt><font size=+1>/</font></tt> <i>command<br>
</i>
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If the range contains (<tt><font size=+1>g</font></tt>) or does not contain (<tt><font size=+1>v</font></tt>) a match for
the expression, set dot to the range and run the command.
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</table>
These may be nested arbitrarily deeply, but only one instance
of either <tt><font size=+1>X</font></tt> or <tt><font size=+1>Y</font></tt> may appear in a single command. An empty command
in an <tt><font size=+1>x</font></tt> or <tt><font size=+1>y</font></tt> defaults to <tt><font size=+1>p</font></tt>; an empty command in <tt><font size=+1>X</font></tt> or <tt><font size=+1>Y</font></tt> defaults
to <tt><font size=+1>f</font></tt>. <tt><font size=+1>g</font></tt> and <tt><font size=+1>v</font></tt> do not have defaults.<br>
<p><font size=+1><b>Miscellany </b></font><br>
<tt><font size=+1>k</font></tt> Set the current file’s mark to the range. Does not set dot.<br>
* <tt><font size=+1>q</font></tt> Quit. It is an error to quit with modified files, but a second
<tt><font size=+1>q</font></tt> will succeed.<br>
* <tt><font size=+1>u</font></tt> <i>n</i> Undo the last <i>n</i> (default 1) top-level commands that changed
the contents or name of the current file, and any other file whose
most recent change was simultaneous with the current file’s change.
Successive <tt><font size=+1>u</font></tt>’s move further back in time. The only commands for
which u is ineffective are <tt><font size=+1>cd</font></tt>, <tt><font size=+1>u</font></tt>, <tt><font size=+1>q</font></tt>, <tt><font size=+1>w</font></tt> and
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<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<tt><font size=+1>D</font></tt>. If <i>n</i> is negative, <tt><font size=+1>u</font></tt> ‘redoes,’ undoing the undo, going forwards
in time again.<br>
</table>
</table>
(empty) If the range is explicit, set dot to the range. If <i>sam</i>
is downloaded, the resulting dot is selected on the screen; otherwise
it is printed. If no address is specified (the command is a newline)
dot is extended in either direction to line boundaries and printed.
If dot is thereby unchanged, it is set to <tt><font size=+1>.+1</font></tt> and
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<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
printed.<br>
</table>
</table>
<p><font size=+1><b>Grouping and multiple changes </b></font><br>
Commands may be grouped by enclosing them in braces <tt><font size=+1>{}</font></tt>. Commands
within the braces must appear on separate lines (no backslashes
are required between commands). Semantically, an opening brace
is like a command: it takes an (optional) address and sets dot
for each sub-command. Commands within the
braces are executed sequentially, but changes made by one command
are not visible to other commands (see the next paragraph). Braces
may be nested arbitrarily.
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When a command makes a number of changes to a file, as in <tt><font size=+1>x/re/c/text/</font></tt>,
the addresses of all changes to the file are computed in the original
file. If the changes are in sequence, they are applied to the
file. Successive insertions at the same address are catenated
into a single insertion composed of the several
insertions in the order applied.<br>
<p><font size=+1><b>The terminal </b></font><br>
What follows refers to behavior of <i>sam</i> when downloaded, that is,
when operating as a display editor on a raster display. This is
the default behavior; invoking <i>sam</i> with the <tt><font size=+1>−d</font></tt> (no download) option
provides access to the command language only.
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Each file may have zero or more windows open. Each window is equivalent
and is updated simultaneously with changes in other windows on
the same file. Each window has an independent value of dot, indicated
by a highlighted substring on the display. Dot may be in a region
not within the window. There is usually
a ‘current window’, marked with a dark border, to which typed
text and editing commands apply. Text may be typed and edited
as in <a href="../man1/rio.html"><i>rio</i>(1)</a>; also the escape key (ESC) selects (sets dot to)
text typed since the last mouse button hit.
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The button 3 menu controls window operations. The top of the menu
provides the following operators, each of which uses one or more
<i>rio</i>-like cursors to prompt for selection of a window or sweeping
of a rectangle. ‘Sweeping’ a null rectangle gets a large window,
disjoint from the command window or the whole
screen, depending on where the null rectangle is.<br>
<tt><font size=+1>new</font></tt> Create a new, empty file.<br>
<tt><font size=+1>zerox</font></tt> Create a copy of an existing window.<br>
<tt><font size=+1>resize</font></tt> As in <i>rio</i>.<br>
<tt><font size=+1>close</font></tt> Delete the window. In the last window of a file, <tt><font size=+1>close</font></tt> is
equivalent to a <tt><font size=+1>D</font></tt> for the file.<br>
<tt><font size=+1>write</font></tt> Equivalent to a <tt><font size=+1>w</font></tt> for the file.
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
Below these operators is a list of available files, starting with
<tt><font size=+1>~~sam~~</font></tt>, the command window. Selecting a file from the list makes
the most recently used window on that file current, unless it
is already current, in which case selections cycle through the
open windows. If no windows are open on the file, the user is
prompted to open one. Files other than <tt><font size=+1>~~sam~~</font></tt> are marked with
one of the characters <tt><font size=+1>−+*</font></tt> according as zero, one, or more windows
are open on the file. A further mark <tt><font size=+1>.</font></tt> appears on the file in
the current window and a single quote, <tt><font size=+1>'</font></tt>, on a file modified since
last write.
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The command window, created automatically when <tt><font size=+1>sam</font></tt> starts, is
an ordinary window except that text typed to it is interpreted
as commands for the editor rather than passive text, and text
printed by editor commands appears in it. The behavior is like
<i>rio</i>, with an ‘output point’ that separates commands being typed
from previous output. Commands typed in the command window apply
to the current open file--the file in the most recently current
window.<br>
<p><font size=+1><b>Manipulating text </b></font><br>
Button 1 changes selection, much like <i>rio</i>. Pointing to a non-current
window with button 1 makes it current; within the current window,
button 1 selects text, thus setting dot. Double-clicking selects
text to the boundaries of words, lines, quoted strings or bracketed
strings, depending on the text at the click.
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Button 2 provides a menu of editing commands:<br>
<tt><font size=+1>cut</font></tt> Delete dot and save the deleted text in the snarf buffer.<br>
<tt><font size=+1>paste</font></tt> Replace the text in dot by the contents of the snarf buffer.<br>
<tt><font size=+1>snarf</font></tt> Save the text in dot in the snarf buffer.<br>
<tt><font size=+1>plumb</font></tt> Send the text in the selection as a plumb message. If the
selection is empty, the white-space-delimited block of text is
sent as a plumb message with a <tt><font size=+1>click</font></tt> attribute defining where
the selection lies (see <a href="../man7/plumb.html"><i>plumb</i>(7)</a>).<br>
<tt><font size=+1>look</font></tt> Search forward for the next occurrence of the literal text
in dot. If dot is the null string, the text in the snarf buffer
is used. The snarf buffer is unaffected.<br>
<tt><font size=+1><rio></font></tt> Exchange snarf buffers with <i>rio</i>.<br>
<tt><font size=+1>/</font></tt><i>regexp</i> Search forward for the next match of the last regular expression
typed in a command. (Not in command window.)<br>
<tt><font size=+1>send</font></tt> Send the text in dot, or the snarf buffer if dot is the null
string, as if it were typed to the command window. Saves the sent
text in the snarf buffer. (Command window only.)<br>
<p><font size=+1><b>External communication </b></font><br>
<i>Sam</i> listens to the <tt><font size=+1>edit</font></tt> plumb port. If plumbing is not active,
on invocation <i>sam</i> creates a named pipe <tt><font size=+1>/srv/sam.</font></tt><i>user</i> which acts
as an additional source of commands. Characters written to the
named pipe are treated as if they had been typed in the command
window.
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<i>B</i> is a shell-level command that causes an instance of <i>sam</i> running
on the same terminal to load the named <i>files</i>. <i>B</i> uses either plumbing
or the named pipe, whichever service is available. If plumbing
is not enabled, the option allows a line number to be specified
for the initial position to display in the last named file
(plumbing provides a more general mechanism for this ability).
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<i>E</i> is a shell-level command that can be used as <tt><font size=+1>$EDITOR</font></tt> in a Unix
environment. It runs <i>B</i> on <i>file</i> and then does not exit until <i>file</i>
is changed, which is taken as a signal that <i>file</i> is done being
edited.<br>
<p><font size=+1><b>Abnormal termination </b></font><br>
If <i>sam</i> terminates other than by a <tt><font size=+1>q</font></tt> command (by hangup, deleting
its window, etc.), modified files are saved in an executable file,
<tt><font size=+1>$HOME/sam.save</font></tt>. This program, when executed, asks whether to write
each file back to a external file. The answer <tt><font size=+1>y</font></tt> causes writing;
anything else skips the file.
</table>
<p><font size=+1><b>FILES </b></font><br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<tt><font size=+1>$HOME/sam.save<br>
$HOME/sam.err<br>
/usr/local/plan9/bin/samsave<br>
</font></tt>
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<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
the program called to unpack <tt><font size=+1>$HOME/sam.save</font></tt>.<br>
</table>
</table>
</table>
<p><font size=+1><b>SOURCE </b></font><br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<tt><font size=+1>/usr/local/plan9/src/cmd/sam</font></tt> source for <i>sam</i> itself<br>
<tt><font size=+1>/usr/local/plan9/src/cmd/samterm</font></tt> source for the separate terminal
part<br>
<tt><font size=+1>/usr/local/plan9/bin/B<br>
/usr/local/plan9/bin/E<br>
</font></tt>
</table>
<p><font size=+1><b>SEE ALSO </b></font><br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<a href="../man1/ed.html"><i>ed</i>(1)</a>, <a href="../man1/sed.html"><i>sed</i>(1)</a>, <a href="../man1/grep.html"><i>grep</i>(1)</a>, <a href="../man1/rio.html"><i>rio</i>(1)</a>, <a href="../man7/regexp.html"><i>regexp</i>(7)</a>.
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
Rob Pike, “The text editor sam”.<br>
</table>
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<tr height=20><td>
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