How can I find files that are bigger/smaller than x bytes?

Question

In a terminal, how can I find files that are bigger or smaller than x bytes?

I suppose I can do something like

find . -exec ls -l {} \;

and then pipe the result to AWK to filter by file size. But shouldn't there be an easier way than this?

Answer 1

Use:

find . -type f -size +4096c

to find files bigger than 4096 bytes.

And :

find . -type f -size -4096c

to find files smaller than 4096 bytes.

Notice the + and - difference after the size switch.

The -size switch explained:

-size n[cwbkMG]

    File uses n units of space. The following suffixes can be used:

    `b'    for 512-byte blocks (this is the default if no suffix  is
                                used)

    `c'    for bytes

    `w'    for two-byte words

    `k'    for Kilobytes       (units of 1024 bytes)

    `M'    for Megabytes    (units of 1048576 bytes)

    `G'    for Gigabytes (units of 1073741824 bytes)

    The size does not count indirect blocks, but it does count
    blocks in sparse files that are not actually allocated. Bear in
    mind that the `%k' and `%b' format specifiers of -printf handle
    sparse files differently. The `b' suffix always denotes
    512-byte blocks and never 1 Kilobyte blocks, which is different
    to the behaviour of -ls.

Answer 2

find . | xargs du -b | perl -ne 'chomp;@p=split(/\s/);print"$p[1] ($p[0])\n"if$p[0]<=4096'

Prints all files that are lesser than or equal to 4096 bytes in size. Simply change the operator and number at the end of this one-liner to change the criteria.

The -b option for du gives you the number of bytes and is equivalent to the apparent size with a block size of 1. Apparent size is usually smaller and may not reflect actual disk-usage.

Answer 3

Greater than 2000 bytes:

du -a . | awk '$1*512 > 2000 {print $2}'

Less than 2000 bytes:

du -a . | awk '$1*512 < 2000 {print $2} '

Answer 4

AWK really is quite easy for this sort of thing. Here are some things you can do with it in relation to file size checking, like you asked:

List files greater than 200 bytes:

ls -l | awk '{if ($5 > 200) print $8}'

List files less than 200 bytes and write the list to a file:

ls -l | awk '{if ($5 < 200) print $8}' | tee -a filelog

List files of 0 bytes, record the list to a file and delete the empty files:

ls -l | awk '{if ($5 == 0) print $8}' | tee -a deletelog | xargs rm