tr.1

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· 1 代码 · 共 78 行

.\" SCCSID: @(#)tr.1	8.1	9/11/90
.TH tr 1 
.SH Name
tr \- translate characters
.SH Syntax
.B tr
[\fB\-cds\fR] [\|\fIstring1\|\fR[\fIstring2\fR\|]\|]
.SH Description
.NXR "tr command"
.NXR "character" "translating"
The
.PN tr
command copies the standard input to the standard output with 
substitution or deletion of selected characters.
Input characters found in 
.I string1
are mapped into the corresponding characters of
.IR string2 .
When 
.I string2
is short it is padded to the length of 
.I string1
by duplicating its last character.
Any combination of the options
.B \-cds
may be used:
.B \-c
complements the set of characters in
.I string1
with respect to the universe of characters
whose ASCII codes are 0 through 0377 octal;
.B \-d
deletes all input characters in
.I string1;
.B \-s
squeezes all strings of repeated output characters that are
in 
.I string2
to single characters.
.PP
In either string the notation
.IB a \- b
means a range of characters from
.I a
to
.I b
in increasing ASCII order.
The backslash character
(\\) followed by 1, 2 or 3 octal digits stands for the
character whose ASCII code is given by those digits.
A \\ followed by any other character stands
for that character.
.PP
The following example creates a list of all
the words in `file1' one per line in `file2',
where a word is taken to be a maximal string of alphabetics.
The second string is quoted
to protect \\ from the Shell.
012 is the ASCII code for newline.
.EX
tr \-cs A\-Za\-z \'\\012\' <file1 >file2
.EE
.SH Options
.IP \fB\-c\fR 5
Translates complements:  string1 to those not 
in string1.
.IP \fB\-d\fR 
Deletes all characters in string1 from output.
.IP \fB\-s\fR 
Squeezes succession of a character in string1 to one in output. 
.SH Restrictions
\`\\0', `\\00', and `\\000' are equivalent for NUL character.
.PP
\`\\012' is
treated as octal 12 and not a NUL followed by characters 1 and 2.
.SH See Also
ed(1), ascii(7), expand(1)