Read filenames using for loop in shell script

Question

In my folder, filenames are like this:

A00001
A00002
.
.
.
A08525

I want to add this file name as an argument:

max = 8525
for i in `seq 2 $max`
do
    python script.py -r filename 
done

I tried like this:

max = 8525
for i in `seq 2 $max`
do
    python script.py -r "A0000$i" #But this work for 1-9 like wise for A000 it will work for 100-999
done

I can not do

for file in A*; 
do 
    echo "$file"; done
done

Because the folder has the same file with three different extensions, like A0000.txt, A0000.pdf, A0000.png, and I want to input only A0000 as an argument.

How can I write the for loop so that I can read all filenames?

@MichaWiedenmann: Thanks, this I though but actually folder has same file with three different extensions. like A0000.txt A0000.pdf A0000.png and I want to input only A0000 without extension — user2129623
– user2129623, Commented Feb 26, 2019 at 14:14
Possible duplicate of stackoverflow.com/questions/54844645/… — tripleee
– tripleee, Commented Feb 26, 2019 at 15:56
Your examples have five digits but then a lot of the rest of the discussion shows four. Which is it? — tripleee
– tripleee, Commented Feb 26, 2019 at 16:03

tripleee · Accepted Answer · 2019-02-26 16:08:04Z

3

You can use printf to pad a number with leading zeros.

for ((i=1; i<=8525; ++i)); do
    printf -v filename "A%05i" "$i"
    python script.py -r "filename"
done

Of course, if the base filenames already exist, you can do

for f in A[0-9][0-9][0-9][0-9][0-9].png; do
    filename=${f%.png}
    python script.py -r "$filename"
done

which neatly avoids hardcoding the upper limit.

edited Feb 26, 2019 at 16:08

answered Feb 26, 2019 at 16:01

tripleee

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1 Comment

tripleee Over a year ago

If you want only four digits after A, obviously use "A%04i" for the format string instead.

chepner · Accepted Answer · 2019-02-26 14:44:45Z

1

Most(?) versions of seq will support outputting 0-padded values.

max=8525
for i in $(seq -w 2 $max); do
  python script.py -r "A$i"
done

Alternately, you can simply loop over the existing files and strip the extension.

for f in A*.txt; do
  f=${f%.txt}
  python script.py -r "$f"
done

answered Feb 26, 2019 at 14:44

chepner

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2 Comments

user2129623 Over a year ago

I want to use it without file extention, I directly used f but that also comes with file extension. Any clue?

chepner Over a year ago

f=${f%.txt} should remove the extension.

nullPointer · Accepted Answer · 2019-02-26 14:18:02Z

1

for file in $(find /path/to/your/files -type f -name "A?????");do python script.py -r "$file"; done

edited Feb 26, 2019 at 14:18

answered Feb 26, 2019 at 14:14

nullPointer

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5 Comments

user2129623 Over a year ago

please check my update question. Thanks for your answer

user2129623 Over a year ago

I tried for file in $(find training2017/ -type f -name "A?????"); do #python script.py -r echo "$file"; done but it did not print anything

nullPointer Over a year ago

@Jhon how many digits are after "A" in the filenames ? , if it's 4, just change the file name pattern to "A????"

tripleee Over a year ago

Why did you put training2017/ in the find command? Nothing else here mentions a subdirectory like that.

user2129623 Over a year ago

@tripleee: All files are in training2017 directory

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