Which command is use to show a list of all files where name starts with either a B or C in the current directory?

How to get the list of files in a directory in a shell script?

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• 1. List different types of files using find and ls
• 2. Capture the output of any command into a bash indexed array, with elements separated by the newline char (\n)
• Which command is use to show a list of all files where name starts with either a B or C in the current directory?
• Which command is used to list all the files in your current directory?
• Which command is used to list all the files and directories start with any character between letter A to letter D?
• What is the command to list all the file names starting with T or S in the current directory?

In addition to the most-upvoted answer by @Ignacio Vazquez-Abrams, consider the following solutions which also all work, depending on what you are trying to do. Note that you can replace "path/to/some/dir" with . in order to search in the current directory.

1. List different types of files using find and ls

References:

1. For find, see this answer. See also my comment here.
2. For ls, see linuxhandbook.com: How to List Only Directories in Linux

Tip: for any of the find examples below, you can pipe the output to sort -V if you'd like it sorted.

Example:

find . -maxdepth 1 -type f | sort -V

List only regular files (-type f) 1 level deep:

# General form find "path/to/some/dir" -maxdepth 1 -type f # In current directory find . -maxdepth 1 -type f

List only symbolic links (-type l) 1 level deep:

# General form find "path/to/some/dir" -maxdepth 1 -type l # In current directory find . -maxdepth 1 -type l

List only directories (-type d) 1 level deep:

Note that for the find example here, we also add -mindepth 1 in order to exclude the current directory, ., which would be printed as . at the top of the directory list otherwise. See here: How to exclude this / current / dot folder from find "type d"

# General form find "path/to/some/dir" -mindepth 1 -maxdepth 1 -type d # In current directory find . -mindepth 1 -maxdepth 1 -type d # OR, using `ls`: ls -d

Combine some of the above: list only regular files and symbolic links (-type f,l) 1 level deep:

Use a comma (,) to separate arguments to -type:

# General form find "path/to/some/dir" -maxdepth 1 -type f,l # In current directory find . -maxdepth 1 -type f,l

2. Capture the output of any command into a bash indexed array, with elements separated by the newline char (\n)

However, $search_dir contains many files with whitespaces in their names. In that case, this script does not run as expected.

This is solved by telling bash to separate elements in the string based on the newline char \n instead of the space char--which is the default IFS (Internal Field Separator--see The Meaning of IFS in Bash Scripting) variable used by bash. To do this, I recommend using the mapfile command.

The bash script static code analyzer tool named shellscript recommends using mapfile or read -r whenever you want to read in a string into a bash array, separating elements based on the newline char (\n). See: https://github.com/koalaman/shellcheck/wiki/SC2206.

Update: to see examples of how to do this with both mapfile and read -r see my answer here: How to read a multi-line string into a regular bash "indexed" array. I now prefer to use read -r instead of mapfile, because mapfile will KEEP any empty lines as elements in the array, if any exist, which I do NOT want, whereas read -r [again, my preference now] will NOT keep empty lines as elements in the array.

(Back to my original answer:)

Here is how to convert a newline-separated string into a regular bash "indexed" array with the mapfile command.

# Capture the output of `ls -1` into a regular bash "indexed" array. # - includes both files AND directories! mapfile -t allfilenames_array <<< "$(ls -1)" # Capture the output of `find` into a regular bash "indexed" array # - includes directories ONLY! # Note: for other `-type` options, see `man find`. mapfile -t dirnames_array \ <<< "$(find . -mindepth 1 -maxdepth 1 -type d | sort -V)"

Notes:

1. We use ls -1 (that's a "dash numeral_one") in order to put each filename on its own line, thereby separating them all by the newline \n char.
2. If you'd like to Google it, <<< is called a "here string" in bash.
3. See mapfile --help, or help mapfile, for help.

Full code example:

From file array_list_all_files_and_directories.sh in my eRCaGuy_hello_world repo:

echo "Output of 'ls -1'" echo "-----------------" ls -1 echo "" # Capture the output of `ls -1` into a regular bash "indexed" array. # - includes both files AND directories! mapfile -t allfilenames_array <<< "$(ls -1)" # Capture the output of `find` into a regular bash "indexed" array # - includes directories ONLY! # Note: for other `-type` options, see `man find` and see my answer here: # https://stackoverflow.com/a/71345102/4561887 mapfile -t dirnames_array \ <<< "$(find . -mindepth 1 -maxdepth 1 -type d | sort -V)" # Get the number of elements in each array allfilenames_array_len="${#allfilenames_array[@]}" dirnames_array_len="${#dirnames_array[@]}" # 1. Now manually print all elements in each array echo "All filenames (files AND dirs) (count = $allfilenames_array_len):" for filename in "${allfilenames_array[@]}"; do echo " $filename" done echo "Dirnames ONLY (count = $dirnames_array_len):" for dirname in "${dirnames_array[@]}"; do # remove the `./` from the beginning of each dirname dirname="$(basename "$dirname")" echo " $dirname" done echo "" # OR, 2. manually print the index number followed by all elements in the array echo "All filenames (files AND dirs) (count = $allfilenames_array_len):" for i in "${!allfilenames_array[@]}"; do printf " %3i: %s\n" "$i" "${allfilenames_array["$i"]}" done echo "Dirnames ONLY (count = $dirnames_array_len):" for i in "${!dirnames_array[@]}"; do # remove the `./` from the beginning of each dirname dirname="$(basename "${dirnames_array["$i"]}")" printf " %3i: %s\n" "$i" "$dirname" done echo ""

Here is the example output of the code block just above being run inside the eRCaGuy_hello_world/python dir of my eRCaGuy_hello_world repo:

eRCaGuy_hello_world/python$ ../bash/array_list_all_files_and_directories.sh Output of 'ls -1' ----------------- autogenerate_c_or_cpp_code.py autogenerated auto_white_balance_img.py enum_practice.py raw_bytes_practice.py slots_practice socket_talk_to_ethernet_device.py textwrap_practice_1.py yaml_import All filenames (files AND dirs) (count = 9): autogenerate_c_or_cpp_code.py autogenerated auto_white_balance_img.py enum_practice.py raw_bytes_practice.py slots_practice socket_talk_to_ethernet_device.py textwrap_practice_1.py yaml_import Dirnames ONLY (count = 3): autogenerated slots_practice yaml_import All filenames (files AND dirs) (count = 9): 0: autogenerate_c_or_cpp_code.py 1: autogenerated 2: auto_white_balance_img.py 3: enum_practice.py 4: raw_bytes_practice.py 5: slots_practice 6: socket_talk_to_ethernet_device.py 7: textwrap_practice_1.py 8: yaml_import Dirnames ONLY (count = 3): 0: autogenerated 1: slots_practice 2: yaml_import

Which command is use to show a list of all files where name starts with either a B or C in the current directory?

Which command is used to list all the files in your current directory?

Which command is used to list all the files and directories start with any character between letter A to letter D?

What is the command to list all the file names starting with T or S in the current directory?