TR(1)                      Commands and Applications                     TR(1)




NAME

       tr - translate characters


SYNOPSIS

       tr [-cs] string1 string2

       tr [-c] -d string1

       tr [-c] -s string1

       tr [-c] -ds string1 string2


DESCRIPTION

       The  tr  utility  copies the standard input to the standard output with
       substitution or deletion of selected characters.

       The following options are available:

              -c     Complements the set of characters  in  string1,  that  is
                     ''-c  ab''  includes every character except for ''a'' and
                     ''b''.

              -d     The -d option causes characters to be  deleted  from  the
                     input.

              -s     The  -s option squeezes multiple occurrences of the char-
                     acters listed in the  last  operand  (either  string1  or
                     string2) in the input into a single instance of the char-
                     acter.  This occurs after all deletion and translation is
                     completed.

       In  the  first  synopsis form, the characters in string1 are translated
       into the characters in string2 where the first character in string1  is
       translated  into  the first character in string2 and so on.  If string1
       is longer than string2, the last character found in string2  is  dupli-
       cated until string1 is exhausted.

       In the second synopsis form, the characters in string1 are deleted from
       the input.

       In the third synopsis form, the characters in string1 are compressed as
       described for the -s option.

       In the fourth synopsis form, the characters in string1 are deleted from
       the input, and the characters in string2 are  compressed  as  described
       for the -s option.

       The following conventions can be used in string1 and string2 to specify
       sets of characters:

              character
                     Any character not described by one of the following  con-
                     ventions represents itself.

              \octal A backslash followed by 1, 2 or 3 octal digits represents
                     a character with that encoded value.  To follow an  octal
                     sequence  with  a digit as a character, left zero-pad the
                     octal sequence to the full 3 octal digits.

              \character
                     A backslash followed by certain special  characters  maps
                     to special values.

                     \a   <alert character>
                     \b   <backspace>
                     \f   <form-feed>
                     \n   <newline>
                     \r   <carriage return>
                     \t   <tab>
                     \v   <vertical tab>

              A backslash followed by any other character maps to that charac-
              ter.

              c1-c2  Represents the range of characters between the range end-
                     points, inclusively.

              [:class:]
                     Represents  all characters belonging to the defined char-
                     acter class.  Class names are:

                     alnum     <alphanumeric characters>
                     alpha     <alphabetic characters>
                     blank     <\t, '' ''>
                     cntrl     <control characters>
                     digit     <numeric characters>
                     graph     <graphic characters>
                     lower     <lower-case alphabetic characters>
                     print     <printable characters>
                     punct     <punctuation characters>
                     space     <\t, \n, \v, \f, \r, '' ''>
                     upper     <upper-case characters>
                     xdigit    <hexadecimal characters>

              With the exception of the ''upper'' and ''lower'' classes, char-
              acters  in  the  classes  are  in  unspecified  order.   In  the
              ''upper'' and  ''lower''  classes,  characters  are  entered  in
              ascending order.

              For  specific  information  as  to  which  ASCII  characters are
              included in these  classes,  see  ctype(3)  and  related  manual
              pages.

              [=equiv=]
                     Represents all characters or collating (sorting) elements
                     belonging to the same equivalence  class  as  equiv.   If
                     there  is  a  secondary  ordering  within the equivalence
                     class, the characters are ordered in ascending  sequence.
                     Otherwise,  they  are ordered after their encoded values.
                     An example of an equivalence class  might  be  ''c''  and
                     ''ch''  in  Spanish;  English has no equivalence classes.
                     Note: because the functions in locale.h  are  not  imple-
                     mented  for the Apple IIGS, English is the only supported
                     language.

              [#*n]  Represents n repeated occurrences of the character repre-
                     sented  by  #.   This  expression  is  only valid when it
                     occurs in string2.  If n is omitted or is zero, it is  be
                     interpreted as large enough to extend string2 sequence to
                     the length of string1.  If n has a leading  zero,  it  is
                     interpreted  as  an  octal  value, otherwise, it's inter-
                     preted as a decimal value.

       The tr utility exits 0 on success, and >0 if an error occurs.


EXAMPLES

       The following examples are shown as given to the shell:

       Create a list of the words in file1, one per  line,  where  a  word  is
       taken to be a maximal string of letters.

       tr -cs '[:alpha:]' '\n' < file1

       Translate the contents of file1 to upper-case.

       tr '[:lower:]' '[:upper:]' < file1

       Strip out non-printable characters from file1.

       tr -cd '[:print:]' < file1


COMPATIBILITY

       System V has historically implemented character ranges using the syntax
       ''[c-c]'' instead of the ''c-c'' used by historic  BSD  implementations
       and  standardized  by  POSIX.  System V shell scripts should work under
       this implementation as long as the range is intended to map in  another
       range, i.e. the command ''tr [a-z] [A-Z]'' will work as it will map the
       ''['' character in string1 to the ''['' character in string2.  However,
       if  the shell script is deleting or squeezing characters as in the com-
       mand ''tr -d [a-z]'', the characters ''['' and '']'' will  be  included
       in the deletion or compression list which would not have happened under
       an historic System V implementation.  Additionally,  any  scripts  that
       depended  on  the  sequence  ''a-z''  to represent the three characters
       ''a'', ''-'' and ''z'' will have to be rewritten as ''a\-z''.

       The tr utility has historically not permitted the manipulation  of  NUL
       bytes  in  its  input  and, additionally, stripped NUL's from its input
       stream.  This implementation has removed this behavior as a bug.

       The tr utility has historically  been  extremely  forgiving  of  syntax
       errors,  for  example,  the  -c  and -s options were ignored unless two
       strings were specified.  This implementation will  not  permit  illegal
       syntax.


STANDARDS

       The  tr  utility  is  expected  to be POSIX.2 compatible.  It should be
       noted that the feature wherein the last character of string2 is  dupli-
       cated if string2 has less characters than string1 is permitted by POSIX
       but is not required.  Shell scripts attempting to be portable to  other
       POSIX  systems should use the ''[#*]'' convention instead of relying on
       this behavior.


VERSION

       This manual page documents tr version 2.0.


ATTRIBUTIONS

       This command was ported from FreeBSD source code for distribution  with
       GNO/ME 2.0.6.


HISTORY

       Version  1.0  (November  3, 1994) of tr was written by Thomas. R. Wyant
       III and distributed as a separate package compatible with GNO and ORCA.



GNO                               August 1997                            TR(1)

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