commit 01455da77e4ef8619ef5fe558bbadca1e8049b69
parent 879921041eb0d12a6789f954db311cc3ef8b892d
Author: tjg <tjg>
Date: Fri, 12 Oct 2001 15:09:49 +0000
fix a few minor problems
Diffstat:
| M | rc.1 | | | 58 | +++++++++++++++++++++++++++++++++------------------------- |
1 file changed, 33 insertions(+), 25 deletions(-)
diff --git a/rc.1 b/rc.1
@@ -166,7 +166,7 @@
rc \- shell
.SH SYNOPSIS
.B rc
-.RB [ \-deilnopsVvx ]
+.RB [ \-deiIlnopsvx ]
.RB [ \-c
.IR command ]
.RI [ arguments ]
@@ -255,7 +255,8 @@ flag is present, or if the input to
is not from a terminal, then
.I rc
will not be in interactive mode. No prompts will be printed, and
-SIGINT will cause
+.Cr SIGINT
+will cause
.I rc
to exit.
.TP
@@ -270,7 +271,7 @@ is a dash
then
.I rc
will behave as a login shell.
-That is, it will try to run commands present in
+That is, it will run commands from
.Cr $home/.rcrc ,
if this file exists, before reading any other input.
.TP
@@ -348,7 +349,7 @@ of shell functions, builtin commands,
or as a file in the directories named by
.Cr $path .
.SS "Background Tasks"
-A command ending with a
+A command ending with
.Cr &
is run in the background; that is,
the shell returns immediately rather than waiting for the command to
@@ -515,6 +516,7 @@ Note that no spaces may appear in these constructs:
.Ds
.Cr "command > [2] file"
.De
+.PP
would send the output of the command to a file named
.Cr [2] ,
with the intended filename appearing in the command's argument list.
@@ -627,9 +629,7 @@ redirection is implemented with some kind of pipe, and since one cannot
.IR lseek (2)
on a pipe, commands that use
.IR lseek (2)
-will hang.
-For example,
-most versions of
+will hang. For example, some versions of
.IR diff (1)
use
.IR lseek (2)
@@ -680,7 +680,7 @@ and performs the command as long as the
.I test
is true.
.TP
-.Ci "for (" var " in" " list" ) " cmd"
+.Ci "for (" var " in " list ) " cmd"
.I rc
sets
.I var
@@ -912,9 +912,10 @@ are two very different things. Assigning the null string to a
variable is a valid operation, but it does not remove its definition.
.Ds
.Cr "null = '' empty = () echo $#null $#empty"
-.Te
+.De
+.PP
produces the output
-.Ts
+.Ds
.Cr "1 0"
.De
.SS "List Concatenation"
@@ -987,7 +988,7 @@ A list may be assigned to a variable, using the notation:
.PP
The special variable
.Cr *
-may be assigned to using this notation;
+may also be assigned to using this notation;
.I rc
has no
.B set
@@ -999,19 +1000,20 @@ digits, may be used as a variable name. Any character except
may be used, but special characters must be quoted.
All user-defined variables are exported into the environment.
.PP
-The value of a variable is referenced with the notation:
+The value of a variable is referenced with the dollar
+.Rc ( $ )
+operator:
.Ds
.Ci $ var
.De
.PP
Any variable which has not been assigned a value returns the null list,
.Cr "()" ,
-when referenced.
-In addition, multiple references are allowed:
+when referenced. Multiple references are allowed:
.Ds
-.Cr a=foo
-.Cr b=a
-.Cr "echo $$b"
+.Cr "a = foo"
+.Cr "b = a"
+.Cr "echo $ $ b"
.De
.PP
prints
@@ -1070,10 +1072,9 @@ Variables may be subscripted with the notation
.PP
where
.I n
-is a list of integers (origin 1).
-The list of subscripts need
-not be in order or even unique.
-Thus,
+is a list of integers (origin 1). The opening parenthesis must
+immediately follow the variable name. The list of subscripts need not
+be in order or even unique. Thus,
.Ds
.Cr "a=(one two three)"
.Cr "echo $a(3 3 3)"
@@ -1121,14 +1122,15 @@ This returns a single-element list, with the number of elements in
.Cr $var .
.SS "Flat Lists"
In order to create a single-element list from a multi-element list,
-with the components space-separated, use
+with the components space-separated, use the dollar-caret
+.Rc ( $^ )
+operator:
.Ds
.Cr $^var
.De
.PP
This is useful when the normal list concatenation rules need to be
-bypassed.
-For example, to append a single period at the end of
+bypassed. For example, to append a single period at the end of
.Cr $path ,
use:
.Ds
@@ -1497,7 +1499,9 @@ Thus:
.Cr "fn sigint {}"
.De
.PP
-causes SIGINT to be ignored by the shell.
+causes
+.Cr SIGINT
+to be ignored by the shell.
Only signals that are being ignored are passed on to programs run by
.IR rc ;
signal functions are not exported.
@@ -1777,12 +1781,14 @@ This function can shift any variable (except
.Ds
.Cr "fn lshift { lshift=$*; *=$$1; shift $lshift(2); $lshift(1)=$* }"
.De
+.PP
With this definition in place,
.Ds
.Cr "walrus = (shoes ships sealing-wax cabbages kings)"
.Cr "lshift walrus 3"
.Cr "whatis walrus"
.De
+.PP
prints
.Ds
.Cr "walrus=(cabbages kings)"
@@ -1801,11 +1807,13 @@ This function allows the separator to be an arbitrary string.
.Cr " echo -n $lflat(2)"
.Cr "}"
.De
+.PP
With this definition in place,
.Ds
.Cr "hops=(uunet mcvax ukc tlg)"
.Cr lflat hops !
.De
+.PP
prints (with no final newline)
.Ds
.Cr uunet!mcvax!ukc!tlg
