'ls -1' : how to list filenames without extension

Question

ls -1 lists my elements like so:

foo.png
bar.png
foobar.png
...

I want it listed without the .png like so:

foo
bar
foobar
...

(the dir only contains .png files)

Can somebody tell me how to use grep in this case?

Purpose: I have a text file where all the names are listed without the extension. I want to make a script that compares the text file with the folder to see which file is missing.

Answer 1

ls -1 | sed -e 's/\.png$//'

The sed command removes (that is, it replaces with the empty string) any string .png found at the end of a filename.

The . is escaped as \. so that it is interpreted by sed as a literal . character rather than the regexp . (which means match any character). The $ is the end-of-line anchor, so it doesn't match .png in the middle of a filename.

Answer 2

You only need the shell for this job.

POSIXly:

for f in *.png; do
    printf '%s\n' "${f%.png}"
done

With zsh:

print -rl -- *.png(:r)

Answer 3

If you just want to use bash:

for i in *; do echo "${i%.png}"; done

You should reach for grep when trying to find matches, not for removing/substituting for that sed is more appropriate:

find . -maxdepth 1 -name "*.png"  | sed 's/\.png$//'

Once you decide you need to create some subdirectories to bring order in your PNG files you can easily change that to:

find . -name "*.png"  | sed 's/\.png$//'

Answer 4

I'd go for basename (assuming the GNU implementation):

basename --suffix=.png -- *.png

Answer 5

Another very similar answer (I'm surprised this particular variant hasn't appeared yet) is:

ls | sed -n 's/\.png$//p'

• You don't need the -1 option to ls, since ls assumes that if the standard output isn't a terminal (it's a pipe, in this case).
• the -n option to sed means ‘don't print the line by default’
• the /p option at the end of the substitution means ‘...and print this line if a substitution was made’.

The net effect of that is to print out only those lines which end in .png, with the .png removed. That is, this also caters to the slight generalisation of the OP’s question, where the directory doesn't contain only .png files.

The sed -n technique is often useful in cases where you might otherwise use grep+sed.

Answer 6

You can use only BASH commands to do that (without any external tools).

for file in *; do echo "${file%.*}"; done 

This is usefully when you're without /usr/bin and works nice for filenames like this.is.image.png and for all extensions.

Answer 7

wasn't it enough?

ls -1 | sed 's/\.png//g'

or in general, this

ls -1 | sed 's/\.[a-z]*//g'

will remove all extensions

Answer 8

It is not safe to parse ls or to pipe find^[1,2]

It is not safe to parse (and to pipe) the output of ls or find, mainly because it possible to find in the file names non usual characters as the newline, the tab... Here a pure shell cycle will work^[cuonglm].
Even the find command not piped with the option -exec will work:

find ./*.png  -exec  basename {} .png  \;

Updates/Notes: You can use find . to search even for the hidden files, or find ./*.png to get only the not hidden ones. With find *.png -exec ... you can have problem in the case it was present a file named .png because find will get it as an option. You can add -maxdepth 0 to avoid to descend in directories named as Dir_01.png, or find ./*.png -prune -exec ... when maxdepth is not allowed (thanks Stéphane). If you want to avoid to list those directories you should add the option -type f (which would also exclude other types of non-regular files). Give it a look to the man for a more complete panorama about all the options available, and remember to check when they are POSIX compliant, for a better portability.

Some words more

It can happen, for example, that copying the title from a document and pasting into the filename, one or more newline will finish in the filename itself. We can be even so unlucky that a title can contain even the key we have to use just before a newline:

The new art of working on .png
files and other formats.

If you want to test, you can create file names like this with the commands

touch "A file with two lines"$'\n'"and This is the second.png"
touch "The new art of working on .png"$'\n'"files and other formats.png"

The simple /bin/ls *png will output ? instead of the non printable characters

A file with two lines?and This is the second.png
The new art of working on .png?files and other formats.png

In all the cases in which you will pipe the output of ls or find the following command will have no hint to understand if the present line comes from a new file name or if it follows a newline character in the precedent file name. A nasty name indeed, but still a legal one.

A shell cycle with a shell Parameter-Expansion , ${parameter%word}, in both the variant with printf or echo will work ^{[cuonglm],[Anthon1]} .

for f in *.png; do printf "%s\n" "${f%.png}" ; done

---

From the man page of the Shell Parameter Expansion ^[3]

${parameter%word}
${parameter%%word}

... the result of the expansion is the value of parameter with the shortest matching pattern (the ‘%’ case) or the longest matching pattern (the ‘%%’ case) deleted.

Answer 9

Use rev:

ls -1 | rev | cut -f 2- -d "." | rev

rev reverses all the strings (lines); you cut everything after the first '.' and rev re-reverses the remnant.

If you want to grep 'alma':

ls -1 | rev | cut -f 2- -d "." | rev | grep 'alma'

Answer 10

If I knew the directory only had files with .png as an extension, I would have just run: ls | awk -F. '{print $1}'

This will return the first "field" for anything where there is a filename.extension.

Example:

[rsingh@rule51 TESTDIR]$ ls
10.png  1.png  2.png  3.png  4.png  5.png  6.png  7.png  8.png  9.png

[rsingh@rule51 TESTDIR]$ ls | awk -F. '{print $1}'
10
1
2
3
4
5
6
7
8
9

Answer 11

according to your comment " I have a text file where where all the names are listed without the extension. I want to make a PHP script that compares the text file with the folder to see which file is missing " :

for file in $(cat yourlist) ; do
  [ -f "${file}.png" ] || {
    echo "$file : listed in yourlist, but missing in the directory"
  }
done
#assumes that filenames have no space...
# otherwise use instead:
#  while IFS= read file ; do ...(same inner loop as above)... ; done < yourlist

and the reverse:

for file in *.png ; do
  grep "^${file%.png}$" yourlist >/dev/null || {
    echo "$file: present in the directory but not listed in yourlist"
  }
done
#I assume there are no spaces/tabs/? before/after names in 'yourlist'. Change the script accordingly if there are some (or sanitize the list)

Answer 12

ls -l | sed 's/\.png$//'

Is the most accurate method as highlighted by @roaima. Without the escaped \.png files named a_png.png would be listed as : a_.

Answer 13

A simple shell line (ksh, bash or zsh; not dash):

set -- *.png; printf '%s\n' "${@%.png}"

A simple function (from No Extension):

ne(){ set -- *.png; printf '%s\n' "${@%.png}"; }

Or a function that remove any extension given (png by default):

ne(){ ext=${1:-png}; set -- *."$ext"; printf '%s\n' "${@%.${ext}}"; }

Use as:

ne jpg

If the output is an asterisk *, no file with that extension exist.

Answer 14

You can try the following feed awk the output of ls your superator is the "." and since all your files will have name.png you print the first column:
ls | awk -F"." '{print $1}'

Answer 15

If you have acccess to sed, this is better as it will strip the last file extension, no matter what it is (png, jpg, tiff, etc...)

ls | sed -e 's/\..*$//'