NAME

tr - character transliteration


SYNOPSIS

tr <infile >outfile from [to]


DESCRIPTION

"TR" copies the standard input to the standard output with
substitution or deletion of selected characters.  Input
characters found in "FROM" are mapped into the corresponding
characters of "TO".
Ranges of characters may be specified by separating
the extremes by a dash.
For example, a-z stands for the string of characters whose ascii
codes run from character a through character z.

If the number of characters
in "FROM" is the same as in "TO", a one to one corresponding
translation will be performed on all occurrences of the characters
in "FROM".
If the number of characters in "FROM" is more than in "TO", the
implication is that the last character in the "TO" string is
to be replicated as often as necessary to make a string as long
as the "FROM" string, and that this replicated character should
be collapsed into only one.  If the "TO" string is missing or
empty, "TR" will take this condition as a request to delete
all occurrences of characters in the "FROM" string.

"TR" differs from the tool "CH" since it deals only with
single characters or ranges of characters, while "CH" deals
with character strings.  For example  tr xy yx  would change
all x's into y's and all y's into x's, whereas ch xy yx
change all the patterns "xy" into "yx".

One of the most common functions of "TR" is to translate
upper case letters to lower case, and vice versa.  Thus,


tr A-Z a-z

would map all upper case letters to lower
case.
Users of systems which cannot pass
both upper and lower case characters on a command line
should remember to include the appropriate escape flags.


FILES

None


SEE ALSO


find, ch, edit, sedit
The "Software Tools" book, p. 51-61.
The "UNIX Programmer's Manual", p. TR(I).



DIAGNOSTICS

"usage: translit from to."


The command line passed to transit is in error.


"from: too large."


The string for "from" is too large.  Current limit is 100 characters
including E0S.


"to: too large."


The string for "to" is too large.  Current limit is 100 characters
including EOS.



AUTHORS

Original code from Kernighan and Plauger's "Software Tools",
with minor modifications by Debbie Scherrer.


BUGS/DEFICIENCIES