

TR                             07/06/78                             TR


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

DIAGNOSTICS


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TR                             07/06/78                             TR


       "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 Plaugers's "Software Tools",
       with modifications by Debbie Scherrer.

BUGS/DEFICIENCIES







































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