[SOLVED] How to convert file size to human readable and print with other columns?

Issue

I want to convert the 5th column in this command output to human readable format. For ex if this is my input :

-rw-rw-r-- 1 bhagyaraj bhagyaraj  280000   Jun 17 18:34 demo1
-rw-rw-r-- 1 bhagyaraj bhagyaraj  2800000  Jun 17 18:34 demo2
-rw-rw-r-- 1 bhagyaraj bhagyaraj  28000000 Jun 17 18:35 demo3

To something like this :

-rw-rw-r--  280K demo1
-rw-rw-r--  2.8M demo2
-rw-rw-r--  28M  demo3

I tried this command, but this will return only the file size column.

ls -l | tail -n +2 |awk '{print $5 | "numfmt --to=si"}'

ls is just for example my use case is very huge and repeated execution must be avoided

Any help would be appreciated :)

Solution

Just use -h --si

  -h, --human-readable       with -l and -s, print sizes like 1K 234M 2G etc.
      --si                   likewise, but use powers of 1000 not 1024

So the command would be

ls -lh --si | tail -n +2

---

If you don't use ls and the command you intend to run doesn't have an option similar to -h --si in ls then numfmt already has the --field option to specify which column you want to format. For example

$ df | LC_ALL=en_US.UTF-8 numfmt --header --field 2-4 --to=si
Filesystem              1K-blocks       Used  Available Use% Mounted on
udev                          66M          0        66M   0% /dev
tmpfs                         14M       7.2K        14M   1% /run
/dev/mapper/vg0-lv--0        4.1G       3.7G       416M  90% /
tmpfs                        5.2K          4       5.2K   1% /run/lock
/dev/nvme2n1p1               524K       5.4K       518K   2% /boot/efi

Unfortunately although numfmt does try to preserve the columnation, it fails if there are some large variation in the line length after inserting group separators like you can see above. So sometimes you might still need to reformat the table with column

df | LC_ALL=en_US.UTF-8 numfmt --header --field 2-4 --to=si | column -t -R 2,3,4,5

The -R 2,3,4,5 option is for right alignment, but some column versions like the default one in Ubuntu don't support it so you need to remove that

---

Alternatively you can also use awk to format only the columns you want, for example column 5 in case of ls

$ ls -l demo* | awk -v K=1e3 -v M=1e6 -v G=1e9 'func format(v) {
  if (v > G) return v/G "G"; else if (v > M) return v/M "M";
  else if (v > K) return v/K "K"; else return v
} { $5 = format($5); print $0 }' | column -t
-rw-rw-r--  1  ph  ph  280K  Jun  18  09:23  demo1
-rw-rw-r--  1  ph  ph  2.8M  Jun  18  09:24  demo2
-rw-rw-r--  1  ph  ph  28M   Jun  18  09:23  demo3
-rw-rw-r--  1  ph  ph  2.8G  Jun  18  09:30  demo4

And column 2, 3, 4 in case of df

# M=1000 and G=1000000 because df output is 1K-block, not bytes
$ df | awk -v M=1000 -v G=1000000 'func format(v) {
  if (v > G) return v/G "G"; else if (v > M) return v/M "M"; else return v
}
{
  # Format only columns 2, 3 and 4, ignore header
  if (NR > 1) { $2 = format($2); $3 = format($3); $4 = format($4) }
  print $0
}' OFS="\t" | column -t
Filesystem              1K-blocks  Used      Available  Use%  Mounted                 on
udev                    65.8273G   0         65.8273G   0%    /dev
tmpfs                   13.1772G   7M        13.1702G   1%    /run
/dev/mapper/vg0-lv--0   4073.78G   3619.05G  415.651G   90%   /
tmpfs                   65.8861G   0         65.8861G   0%    /dev/shm
tmpfs                   5.12M      4         5.116M     1%    /run/lock
tmpfs                   65.8861G   0         65.8861G   0%    /sys/fs/cgroup
/dev/nvme2n1p2          999.32M    363.412M  567.096M   40%   /boot

Answered By - phuclv

Answer Checked By - Marilyn (WPSolving Volunteer)