


SORT(1L)						 SORT(1L)


NNAAMMEE
       sort - sort lines of text files

SSYYNNOOPPSSIISS
       ssoorrtt  [-cmus] [-t separator] [-o output-file] [-T tempdir]
       [-bdfiMnr] [+POS1 [-POS2]] [-k POS1[,POS2]] [file...]

DDEESSCCRRIIPPTTIIOONN
       This manual page documents the GNU version of ssoorrtt.   ssoorrtt
       sorts,  merges,	or  compares all the lines from the given
       files, or the standard input if no  files  are  given.	A
       file  name  of `-' means standard input.	By default, ssoorrtt
       writes the results to the standard output.

       ssoorrtt has three modes of	operation:  sort  (the	default),
       merge,  and  check  for sortedness.  The following options
       change the operation mode:

       _-_c     Check whether the given files are	already  sorted:
	      if  they are not all sorted, print an error message
	      and exit with a status of 1.

       _-_m     Merge the given files by sorting them as	a  group.
	      Each  input  file	should	already  be individually
	      sorted.  It always works to sort instead of  merge;
	      merging  is  provided  because it is faster, in the
	      case where it works.

       A pair of lines is compared as follows: if any key  fields
       have been specified, ssoorrtt compares each pair of fields, in
       the order specified on the command line, according to  the
       associated  ordering  options, until a difference is found
       or no fields are left.

       If any of the global options _M_b_d_f_i_n_r are given but no  key
       fields  are  specified,	ssoorrtt  compares	the  entire lines
       according to the global options.

       Finally, as a last resort when all keys compare equal  (or
       if  no  ordering options were specified at all), ssoorrtt com-
       pares  the  lines  byte	by  byte  in  machine	collating
       sequence.  The last resort comparison honors the _-_r global
       option.	The _-_s (stable) option disables this  last-resort
       comparison so that lines in which all fields compare equal
       are left in their original relative order.  If  no  fields
       or global options are specified, _-_s has no effect.

       GNU  ssoorrtt  has  no limits on input line length or restric-
       tions on bytes allowed within lines.  In addition, if  the
       final  byte  of	an  input file is not a newline, GNU ssoorrtt
       silently supplies one.

       If the environment variable TTMMPPDDIIRR is set, ssoorrtt uses it as
       the  directory  in which to put temporary files instead of



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SORT(1L)						 SORT(1L)


       the default, /tmp.  The _-_T _t_e_m_p_d_i_r option is  another  way
       to  select the directory for temporary files; it overrides
       the environment variable.

       The following options affect the ordering of output lines.
       They  may  be  specified globally or as part of a specific
       key field.  If no key fields are specified, global options
       apply  to comparison of entire lines; otherwise the global
       options are inherited by key fields that	do  not  specify
       any special options of their own.

       _-_b     Ignore  leading  blanks  when  finding sort keys in
	      each line.

       _-_d     Sort in `phone directory' order: ignore all charac-
	      ters  except  letters, digits and blanks when sort-
	      ing.

       _-_f     Fold lower  case	characters  into  the  equivalent
	      upper  case  characters  when  sorting so that, for
	      example, `b' is sorted the same way `B' is.

       _-_i     Ignore characters outside the ASCII range	040-0176
	      octal (inclusive) when sorting.

       _-_M     An  initial  string,  consisting	of  any amount of
	      white space, followed by three letters abbreviating
	      a	month name, is folded to UPPER case and compared
	      in the order `JAN' < `FEB' < ... < `DEC.'	Invalid
	      names compare low to valid names.

       _-_n     Compare  according  to  arithmetic value an initial
	      numeric string consisting of optional white  space,
	      an  optional  -  sign,  and  zero	or  more digits,
	      optionally followed by a decimal point and zero  or
	      more digits.

       _-_r     Reverse  the  result  of	comparison, so that lines
	      with greater key values appear earlier in the  out-
	      put instead of later.

       Other options are:

       _-_o _o_u_t_p_u_t_-_f_i_l_e
	      Write output to _o_u_t_p_u_t_-_f_i_l_e instead of to the stan-
	      dard output.  If _o_u_t_p_u_t_-_f_i_l_e is one  of  the  input
	      files,  ssoorrtt  copies  it to a temporary file before
	      sorting and writing the output to _o_u_t_p_u_t_-_f_i_l_e.

       _-_t _s_e_p_a_r_a_t_o_r
	      Use character _s_e_p_a_r_a_t_o_r as the field separator when
	      finding  the  sort  keys in each line.  By default,
	      fields are separated by the empty string between	a
	      non-whitespace	character    and   a   whitespace



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	      character.  That is to say, given the input line	`
	      foo  bar',  ssoorrtt breaks it into fields ` foo' and `
	      bar'.  The field separator is not considered to  be
	      part  of	either	the  field preceding or the field
	      following it.

       _-_u     For the default case or the _-_m option, only  output
	      the  first  of  a	sequence  of  lines that compare
	      equal.  For the _-_c option, check that  no	pair  of
	      consecutive lines compares equal.

       _+_P_O_S_1 _[_-_P_O_S_2_]
	      Specify  a field within each line to use as a sort-
	      ing key.	The field consists of the portion of  the
	      line starting at POS1 and up to (but not including)
	      POS2 (or to the end of the  line	if  POS2  is  not
	      given).	The  fields  and  character positions are
	      numbered starting with 0.

       _-_k _P_O_S_1_[_,_P_O_S_2_]
	      An alternate syntax for  specifying  sorting  keys.
	      The  fields  and	character  positions are numbered
	      starting with 1.

       A position has the form _f._c, where _f is the number of  the
       field  to  use  and _c is the number of the first character
       from the beginning of the field (for _+_p_o_s) or from the end
       of  the previous field (for _-_p_o_s).  The ._c part of a posi-
       tion may be omitted in which case it is taken  to  be  the
       first  character	in the field.	If the _-_b option has been
       given, the ._c part of a	field  specification  is  counted
       from  the first nonblank character of the field (for _+_p_o_s)
       or from the first nonblank character following the  previ-
       ous field (for _-_p_o_s).

       A  _+_p_o_s	or  _-_p_o_s argument may also have any of the option
       letters _M_b_d_f_i_n_r appended to it, in which case  the  global
       ordering	options  are not used for that particular field.
       The _-_b option may be independently attached to  either  or
       both  of the _+_p_o_s and _-_p_o_s parts of a field specification,
       and if it is inherited from the global options it will  be
       attached	to  both.   If	a  _-_n or _-_M option is used, thus
       implying a _-_b option, the _-_b option is taken to	apply  to
       both  the  _+_p_o_s and the _-_p_o_s parts of a key specification.
       Keys may span multiple fields.

CCOOMMPPAATTIIBBIILLIITTYY
       Historical (BSD and System V) implementations of ssoorrtt have
       differed in their interpretation of some options, particu-
       larly _-_b, _-_f, and _-_n.  GNU sort follows the  POSIX  behav-
       ior,  which is usually (but not always!) like the System V
       behavior.  According to POSIX _-_n	no  longer  implies  _-_b.
       For  consistency,  _-_M  has  been	changed in the same way.
       This may affect the  meaning  of	character  positions  in



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       field  specifications in obscure cases.	If this bites you
       the fix is to add an explicit _-_b.

BBUUGGSS
       The  different  meaning	of  field  numbers  depending  on
       whether	_-_k is used is confusing.  It's all POSIX's fault!



















































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