glenda.party
term% ls -F
term% cat index.txt
SORT(1)                     General Commands Manual                    SORT(1)



NAME
       sort - sort and/or merge files

SYNOPSIS
       sort [ -cmuMbdfinrwtx ] [ +pos1 [ -pos2 ] ...  ] ...  [ -k pos1 [ ,pos2
       ] ] ...  [ -o output ] [ -T dir ...  ] [ option ...  ] [ file ...  ]

DESCRIPTION
       Sort sorts lines of all the files together and writes the result on the
       standard  output.   If  no input files are named, the standard input is
       sorted.

       The default sort key is an entire line.  Default  ordering  is  lexico‐
       graphic  by  runes.  The ordering is affected globally by the following
       options, one or more of which may appear.

       -M     Compare as months.  The first three non-white  space  characters
              of  the field are folded to upper case and compared so that pre‐
              cedes etc.  Invalid fields compare low to

       -b     Ignore leading white space (spaces and tabs)  in  field  compar‐
              isons.

       -d     `Phone  directory' order: only letters, accented letters, digits
              and white space are significant in comparisons.

       -f     Fold lower case letters onto upper  case.   Accented  characters
              are folded to their non-accented upper case form.

       -i     Ignore  characters  outside  the ASCII range 040-0176 in non-nu‐
              meric comparisons.

       -w     Like -i, but ignore only tabs and spaces.

       -n     An initial numeric string, consisting of optional  white  space,
              optional  plus  or  minus sign, and zero or more digits with op‐
              tional decimal point, is sorted by arithmetic value.

       -g     Numbers, like -n but with optional e-style exponents, are sorted
              by value.

       -r     Reverse the sense of comparisons.

       -tx    `Tab character' separating fields is x.

       The  notation  +pos1 -pos2 restricts a sort key to a field beginning at
       pos1 and ending just before pos2.  Pos1 and pos2  each  have  the  form
       m.n,  optionally followed by one or more of the flags Mbdfginr, where m
       tells a number of fields to skip from the beginning of the line  and  n
       tells a number of characters to skip further.  If any flags are present
       they override all the global ordering options for this key.  A  missing
       .n  means .0; a missing -pos2 means the end of the line.  Under the -tx
       option, fields are strings separated by x; otherwise  fields  are  non-
       empty  strings separated by white space.  White space before a field is
       part of the field, except under option -b.  A b flag  may  be  attached
       independently to pos1 and pos2.

       The  notation -k pos1[,pos2] is how POSIX sort defines fields: pos1 and
       pos2 have the same format but different meanings.  The value  of  m  is
       origin 1 instead of origin 0 and a missing .n in pos2 is the end of the
       field.

       When there are multiple sort keys, later keys are compared  only  after
       all earlier keys compare equal.  Lines that otherwise compare equal are
       ordered with all bytes significant.

       These option arguments are also understood:

       -c         Check that the single input file is sorted according to  the
                  ordering  rules;  give  no  output unless the file is out of
                  sort.

       -m         Merge; assume the input files are already sorted.

       -u         Suppress all but one in each set of  equal  lines.   Ignored
                  bytes and bytes outside keys do not participate in this com‐
                  parison.

       -o         The next argument is the name of an output file to  use  in‐
                  stead  of the standard output.  This file may be the same as
                  one of the inputs.

       -Tdir      Put temporary files in dir rather than in /tmp.

EXAMPLES
       Print in alphabetical order all the unique spellings
              in a list of words where capitalized words differ  from  uncapi‐
              talized.

       Print the users file
              sorted by user name (the second colon-separated field).

       Print the first instance of each month in an already sorted file.
              Options -um with just one input file make the choice of a unique
              representative from a set of equal lines predictable.

       grep -n '^' input | sort -t: +1f +0n | sed 's/[0-9]*://'
              A stable sort: input lines that compare equal will come  out  in
              their original order.

FILES
       /tmp/sort.<pid>.<ordinal>

SOURCE
       /sys/src/cmd/sort.c

SEE ALSO
       uniq(1), look(1)

DIAGNOSTICS
       Sort comments and exits with non-null status for various trouble condi‐
       tions and for disorder discovered under option -c.

BUGS
       An external null character can be confused with an internally generated
       end-of-field  character.  The result can make a sub-field not sort less
       than a longer field.

       Some of the options, e.g.  -i and -M, are hopelessly provincial.



                                                                       SORT(1)