I want to sort a unix file by the id column but when I use sort -k4,4 or -k4,4n I do not get the expected result.
The column of interest should be sorted like this:
id1
id2
id3
id4
etc.
Instead it is sorted like this when i do sort -k4,4
id1
id10
id100
id1000
id10000
id10001
etc.
My unix version uses the following sort function:
sort --help
Usage: sort [OPTION]... [FILE]...
Write sorted concatenation of all FILE(s) to standard output.
Mandatory arguments to long options are mandatory for short options too.
Ordering options:
-b, --ignore-leading-blanks ignore leading blanks
-d, --dictionary-order consider only blanks and alphanumeric characters
-f, --ignore-case fold lower case to upper case characters
-g, --general-numeric-sort compare according to general numerical value
-i, --ignore-nonprinting consider only printable characters
-M, --month-sort compare (unknown) < `JAN' < ... < `DEC'
-n, --numeric-sort compare according to string numerical value
-r, --reverse reverse the result of comparisons
Other options:
-c, --check check whether input is sorted; do not sort
-k, --key=POS1[,POS2] start a key at POS1, end it at POS2 (origin 1)
-m, --merge merge already sorted files; do not sort
-o, --output=FILE write result to FILE instead of standard output
-s, --stable stabilize sort by disabling last-resort comparison
-S, --buffer-size=SIZE use SIZE for main memory buffer
-t, --field-separator=SEP use SEP instead of non-blank to blank transition
-T, --temporary-directory=DIR use DIR for temporaries, not $TMPDIR or /tmp;
multiple options specify multiple directories
-u, --unique with -c, check for strict ordering;
without -c, output only the first of an equal run
-z, --zero-terminated end lines with 0 byte, not newline
--help display this help and exit
--version output version information and exit
Use the -V
or --version-sort
option for version sort
sort -V -k4,4 file.txt
Example:
$ cat file.txt
id5
id3
id100
id1
id10
Ouput:
$ sort -V file.txt
id1
id3
id5
id10
id100
EDIT:
If your implementation of sort
doesn't have the -V
option then a work-around using sed
to remove id
so a numeric sort -n
can be done and then replace id
back with sed
, like this:
sed -E 's/id([0-9]+)/\1/' file.txt | sort -n -k4,4 | sed -E 's/( *)([0-9]+)( *|$)/\1id\2\3/'
Note: this solution is dependent on the data, only works if no columns containing purely numbers are found before the ID column.
As sudo_o has already mentioned , the easiest would be to use --version-sort
which does natural sorting of numbers that occur within text.
If your version of sort
does not have that option, a hacky way to approach this would be to temporarily remove the "id" prefix before a sort, then replace them. Here's one way, using awk:
awk 'sub("^id", "", $4)' file.txt | sort -k4,4n | awk 'sub("^", "id", $4)'
If your sort
supports it, you can also use the syntax FC to use specific characters from a field.
This would sort on field 4, from chars 3 to 10, numerical value:
sort -bn -k 4.3,4.10 file
And this would sort on field 4, from chars 3 to end of field, numerical value:
sort -bn -k 4.3,4 file
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.