NAME

sort − sort and/or merge files

SYNOPSIS

sort [ [−cmu] [−ooutput] [−ykmem] [−zrecsz] [−dfiMnrl] [−tbx] [+pos1 [−pos2]]] [files]

DESCRIPTION

Sort sorts lines of all the named files together and writes the result on the standard output.  The standard input is read if − is used as a file name or no input files are named. 

Comparisons are based on one or more sort keys extracted from each line of input.  By default, there is one sort key, the entire input line, and ordering is lexicographic by bytes in machine collating sequence. 

International Support:  Specifying the −l option causes sorting to be performed using the collation sequence associated with the specified language.  If the language is not specified or is set to n-computer, the ordering is lexicographic by bytes in machine-collating sequence. 

If the user’s language includes two-byte characters, one-byte characters are machine-collated before two-byte characters. 

The following options alter the default behavior:

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

−m Merge only, the input files are already sorted. 

−u Unique: suppress all but one in each set of lines having equal keys. 

−ooutput The argument given is the name of an output file to use instead of the standard output.  This file may be the same as one of the inputs.  There may be optional blanks between −o and output. 

−ykmem The amount of main memory used by the sort has a large impact on its performance.  Sorting a small file in a large amount of memory is a waste.  If this option is omitted, sort begins using a system default memory size, and continues to use more space as needed.  If this option is presented with a value, kmem, sort will start using that number of kilobytes of memory, unless the administrative minimum or maximum is violated, in which case the corresponding extremum will be used.  Thus, −y0 is guaranteed to start with minimum memory.  By convention, −y (with no argument) starts with maximum memory. 

−zrecsz The size of the longest line read is recorded in the sort phase so buffers can be allocated during the merge phase.  If the sort phase is omitted via the −c or −m options, a popular system default size will be used.  Lines longer than the buffer size will cause sort to terminate abnormally.  Supplying the actual number of bytes in the longest line to be merged (or some larger value) will prevent abnormal termination. 

The following options override the default ordering rules. 

−d “Dictionary” order: only letters, digits and blanks (spaces and tabs) are significant in comparisons. 

−f Fold lowercase letters into uppercase.  The -f option is ignored if a language other than n-computer is specified. 

−i Ignore characters outside the ASCII range 040-0176 in non-numeric comparisons.  The -i option will be ignored if a language other than n-computer is specified. 

−M Compare as months.  The first three non-blank characters of the field are folded to uppercase and compared so that “JAN” < “FEB” < ... < “DEC”.  An invalid field is considered less than “JAN”.  The −M option implies the −b option (see below). 

−n An initial numeric string, consisting of optional blanks, optional minus sign, and zero or more digits with optional decimal point, is sorted by arithmetic value.  The −n option implies the −b option (see below).  Note that the −b option is only effective when restricted sort key specifications are in effect. 

−r Reverse the sense of comparisons. 

The following option applies to International Support (see above). 

−l Collate characters using the collation rules associated with the user’s LANG variable, see environ(5).

When ordering options appear before restricted sort key specifications, the requested ordering rules are applied globally to all sort keys.  When attached to a specific sort key (described below), the specified ordering options override all global ordering options for that key. 

The notation +pos1 −pos2 restricts a sort key to one beginning at pos1 and ending at pos2. The characters at positions pos1 and pos2 are included in the sort key (provided that pos2 does not precede pos1). A missing −pos2 means the end of the line. 

Specifying pos1 and pos2 involves the notion of a field, a minimal sequence of characters followed by a field separator or a new-line.  By default, the first blank (space or tab) of a sequence of blanks acts as the field separator.  All blanks in a sequence of blanks are considered to be part of the next field; for example, all blanks at the beginning of a line are considered to be part of the first field.  The treatment of field separators can be altered using the options:

−tx Use x as the field separator character; x is not considered to be part of a field (although it may be included in a sort key).  Each occurrence of x is significant (e.g., xx delimits an empty field). 

−b Ignore leading blanks when determining the starting and ending positions of a restricted sort key.  If the −b option is specified before the first +pos1 argument, it will be applied to all +pos1 arguments.  Otherwise, the b flag may be attached independently to each +pos1 or −pos2 argument (see below). 

Pos1 and pos2 each have the form m.n optionally followed by one or more of the flags bdfinr.  A starting position specified by +m.n is interpreted to mean the n+1st character in the m+1st field. A missing .n means .0, indicating the first character of the m+1st field. If the b flag is in effect, n is counted from the first non-blank in the m+1st field; +m.0b refers to the first non-blank character in the m+1st field.

A last position specified by −m.n is interpreted to mean the nth character (including separators) after the last character of the m th field.  A missing .n means .0, indicating the last character of the mth field. If the b flag is in effect, n is counted from the last leading blank in the m+1st field; −m.1b refers to the first non-blank in the m+1st 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. 

EXAMPLES

Sort the contents of infile with the second field as the sort key:

sort +1 −2 infile

Sort, in reverse order, the contents of infile1 and infile2, placing the output in outfile and using the first character of the second field as the sort key:

sort −r −o outfile +1.0 −1.2 infile1 infile2

Sort, in reverse order, the contents of infile1 and infile2, using the first non-blank character of the second field as the sort key:

sort −r +1.0b −1.1b infile1 infile2

Print the password file (passwd(4)) sorted by the numeric user ID (the third colon-separated field):

sort −t: +2n −3 /etc/passwd

Print the lines of the already sorted file infile, suppressing all but the first occurrence of lines having the same third field (the options −um with just one input file make the choice of a unique representative from a set of equal lines predictable):

sort −um +2 −3 infile

FILES

/usr/tmp/stm??? 

SEE ALSO

comm(1), join(1), uniq(1), collate8(4), environ(5), hpnls(5), langid(5). 

DIAGNOSTICS

Comments and exits with non-zero status for various trouble conditions (e.g., when input lines are too long), and for disorder discovered under the −c option. 

When the last line of an input file is missing a new-line character, sort appends one, prints a warning message, and continues. 

If there is an error in accessing the tables containing the collation rules for the specified language, sort prints a warning message and defaults to n-computer. 

The −d option recognizes ASCII characters only.  If a language other than n-computer is specified with the -d option, sort prints a warning message and defaults to n-computer. 

The −M option compares American month names only.  If a language other than n-computer is specified with the -M option, sort prints a warning message and defaults to n-computer. 

The −n option only recognizes the English radix character (decimal point) in numeric comparisons.  If a language other than n-computer is specified with the -n option, sort prints a warning message and defaults to n-computer. 

BUGS

When using the specified ordering option(s) with two-byte characters, pos1 and pos2 must specify byte position, not character position. 

The −t option only recognizes a character encoded in one byte as a field separator character. 

INTERNATIONAL SUPPORT

8- and 16-bit data, 8-bit file names, messages. 

Hewlett-Packard Company  —  Version B.1,  May 11, 2021