bash script, create array of all files in a directory

Question

I have a directory myDir of many .html files. I am trying to create an array of all the files in the directory so I might be able to index the array and be able to refer to particular html files in the directory. I have tried the following line:

myFileNames=$(ls ~/myDir)

for file in $myFileNames; 
#do something

but I want to be able to have a counter variable and have logic like the following:

 while $counter>=0;
   #do something to myFileNames[counter]

I am quite new to shell scripting and am unable to figure out how to achieve this hence would appreciate any help regarding this matter.

anubhava · Answer 1 · 2020-09-01T09:32:17.433

60

You can do:

# use nullglob in case there are no matching files
shopt -s nullglob

# create an array with all the filer/dir inside ~/myDir
arr=(~/myDir/*)

# iterate through array using a counter
for ((i=0; i<${#arr[@]}; i++)); do
    #do something to each element of array
    echo "${arr[$i]}"
done

You can also do this for iteration of array:

for f in "${arr[@]}"; do
   echo "$f"
done

edited Sep 01 '20 at 09:32

answered Feb 10 '14 at 03:17

anubhava

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1

If you want to limit the number of times the for loop is run you could make the following ammendment: counter=10 for ((i=0; i<${#arr[@]} && i – andypea Feb 10 '14 at 03:25
6

Actually **`shopt -s nullglob`** can be used before array creation to avoid getting any false result. – anubhava Feb 10 '14 at 03:37
Maybe you can tell how to filter files with certain extension? – zygimantus Jan 05 '16 at 11:34
1

To match files with `txt` extension use `arr=(~/myDir/*.txt)` at top – anubhava Jan 05 '16 at 13:57
This solution works for me except that the array contains the file path along with the file name. How would I store just the file name and not the path? Thanks in advance! – Jerry C May 30 '16 at 19:51
1

Then it is better to do `cd myDir` and then `arr=(*.txt)` – anubhava May 30 '16 at 21:25
btw, if there is no matching file the array will just contain `~/myDir/*`.. Might be unexpected. – Henk Poley Sep 01 '20 at 08:56
2

@HenkPoley: Good point. I have added `shopt -s nullglob` for this. – anubhava Sep 01 '20 at 09:32
what if files need sudo to list them? e.g. `sudo ls`, how would i use shopt and set the array for this? – blamb Aug 25 '23 at 18:42
Run this script with `sudo` – anubhava Aug 25 '23 at 19:02

score 8 · Answer 2 · edited Aug 23 '20 at 18:35

8

Your solution will work for generating the array. Instead of using a while loop, use a for loop:

#!/bin/bash
files=($( ls * )) #Add () to convert output to array
counter=0
for i in $files ; do
  echo Next: $i
  let counter=$counter+1
  echo $counter
done

edited Aug 23 '20 at 18:35

Community

1
1

answered Feb 10 '14 at 03:20

Paul Hicks

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Use IFS to set the field separator in this case. So long as IFS doesn't include space, then you should be good. – Paul Hicks Dec 17 '18 at 00:32
OP didn't mention this as being part of the criteria :) – Paul Hicks Dec 17 '18 at 02:08

score 1 · Answer 3 · answered Aug 23 '20 at 19:26

1

# create an array with all the filer/dir inside ~/myDir
arr=(~/myDir/*)

# iterate through array indexes to get 'counter'
for counter in ${!arr[*]}; do
    echo $counter           # show index
    echo "${arr[counter]}"  # show value
done

answered Aug 23 '20 at 19:26

Ivan

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bash script, create array of all files in a directory

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