Recursively counting files in a Linux directory

Question

How can I recursively count files in a Linux directory?

I found this:

find DIR_NAME -type f ¦ wc -l

But when I run this it returns

Answer 1

Since filenames in UNIX may contain newlines (yes, newlines), wc -l might count too many files. I would print a dot for every file and then count the dots:

find DIR_NAME -type f -printf "." | wc -c

Answer 2

For directories with spaces in the name ... (based on various answers above) -- recursively print directory name with number of files within:

find . -mindepth 1 -type d -print0 | while IFS= read -r -d '' i ; do echo -n $i": " ; ls -p "$i" | grep -v / | wc -l ; done

---

Example (formatted for readability):

pwd
  /mnt/Vancouver/Programming/scripts/claws/corpus

ls -l
  total 8
  drwxr-xr-x 2 victoria victoria 4096 Mar 28 15:02 'Catabolism - Autophagy; Phagosomes; Mitophagy'
  drwxr-xr-x 3 victoria victoria 4096 Mar 29 16:04 'Catabolism - Lysosomes'

ls 'Catabolism - Autophagy; Phagosomes; Mitophagy'/ | wc -l
  138

## 2 dir (one with 28 files; other with 1 file):
ls 'Catabolism - Lysosomes'/ | wc -l
  29

The directory structure is better visualized using tree:

tree -L 3 -F .
  .
  ├── Catabolism - Autophagy; Phagosomes; Mitophagy/
  │   ├── 1
  │   ├── 10
  │   ├── [ ... SNIP! (138 files, total) ... ]
  │   ├── 98
  │   └── 99
  └── Catabolism - Lysosomes/
      ├── 1
      ├── 10
      ├── [ ... SNIP! (28 files, total) ... ]
      ├── 8
      ├── 9
      └── aaa/
          └── bbb

  3 directories, 167 files

man find | grep mindep
  -mindepth levels
    Do not apply any tests or actions at levels less than levels
    (a non-negative integer).  -mindepth 1 means process all files
    except the starting-points.

ls -p | grep -v / (used below) is from answer 2 at https://unix.stackexchange.com/questions/48492/list-only-regular-files-but-not-directories-in-current-directory

find . -mindepth 1 -type d -print0 | while IFS= read -r -d '' i ; do echo -n $i": " ; ls -p "$i" | grep -v / | wc -l ; done
./Catabolism - Autophagy; Phagosomes; Mitophagy: 138
./Catabolism - Lysosomes: 28
./Catabolism - Lysosomes/aaa: 1

---

Applcation: I want to find the max number of files among several hundred directories (all depth = 1) [output below again formatted for readability]:

date; pwd
    Fri Mar 29 20:08:08 PDT 2019
    /home/victoria/Mail/2_RESEARCH - NEWS

time find . -mindepth 1 -type d -print0 | while IFS= read -r -d '' i ; do echo -n $i": " ; ls -p "$i" | grep -v / | wc -l ; done > ../../aaa
    0:00.03

[victoria@victoria 2_RESEARCH - NEWS]$ head -n5 ../../aaa
    ./RNA - Exosomes: 26
    ./Cellular Signaling - Receptors: 213
    ./Catabolism - Autophagy; Phagosomes; Mitophagy: 138
    ./Stress - Physiological, Cellular - General: 261
    ./Ancient DNA; Ancient Protein: 34

[victoria@victoria 2_RESEARCH - NEWS]$ sed -r 's/(^.*): ([0-9]{1,8}$)/\2: \1/g' ../../aaa | sort -V | (head; echo ''; tail)

    0: ./Genomics - Gene Drive
    1: ./Causality; Causal Relationships
    1: ./Cloning
    1: ./GenMAPP 2
    1: ./Pathway Interaction Database
    1: ./Wasps
    2: ./Cellular Signaling - Ras-MAPK Pathway
    2: ./Cell Death - Ferroptosis
    2: ./Diet - Apples
    2: ./Environment - Waste Management

    988: ./Genomics - PPM (Personalized & Precision Medicine)
    1113: ./Microbes - Pathogens, Parasites
    1418: ./Health - Female
    1420: ./Immunity, Inflammation - General
    1522: ./Science, Research - Miscellaneous
    1797: ./Genomics
    1910: ./Neuroscience, Neurobiology
    2740: ./Genomics - Functional
    3943: ./Cancer
    4375: ./Health - Disease 

sort -V is a natural sort. ... So, my max number of files in any of those (Claws Mail) directories is 4375 files. If I left-pad (https://stackoverflow.com/a/55409116/1904943) those filenames -- they are all named numerically, starting with 1, in each directory -- and pad to 5 total digits, I should be ok.

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Addendum

Find the total number of files, subdirectories in a directory.

$ date; pwd
Tue 14 May 2019 04:08:31 PM PDT
/home/victoria/Mail/2_RESEARCH - NEWS

$ ls | head; echo; ls | tail
Acoustics
Ageing
Ageing - Calorie (Dietary) Restriction
Ageing - Senescence
Agriculture, Aquaculture, Fisheries
Ancient DNA; Ancient Protein
Anthropology, Archaeology
Ants
Archaeology
ARO-Relevant Literature, News

Transcriptome - CAGE
Transcriptome - FISSEQ
Transcriptome - RNA-seq
Translational Science, Medicine
Transposons
USACEHR-Relevant Literature
Vaccines
Vision, Eyes, Sight
Wasps
Women in Science, Medicine

$ find . -type f | wc -l
70214    ## files

$ find . -type d | wc -l
417      ## subdirectories

Answer 3

To determine how many files there are in the current directory, put in ls -1 | wc -l. This uses wc to do a count of the number of lines (-l) in the output of ls -1. It doesn't count dotfiles. Please note that ls -l (that's an "L" rather than a "1" as in the previous examples) which I used in previous versions of this HOWTO will actually give you a file count one greater than the actual count. Thanks to Kam Nejad for this point.

If you want to count only files and NOT include symbolic links (just an example of what else you could do), you could use ls -l | grep -v ^l | wc -l (that's an "L" not a "1" this time, we want a "long" listing here). grep checks for any line beginning with "l" (indicating a link), and discards that line (-v).

Relative speed: "ls -1 /usr/bin/ | wc -l" takes about 1.03 seconds on an unloaded 486SX25 (/usr/bin/ on this machine has 355 files). "ls -l /usr/bin/ | grep -v ^l | wc -l" takes about 1.19 seconds.

Source: http://www.tldp.org/HOWTO/Bash-Prompt-HOWTO/x700.html