@hackage lsfrom2.0

List directory files starting from a specific name

lsfrom

lsfrom lists the files and/or dirs in a directory starting from the given filename or the next one after that, using the current locale collation order.

Tutorial

Consider a directory with a few files:

$ ls
A b B C

(lsfrom is typically more useful in larger directories, but to keep things simple let's use a small example here.)

Let's list the files after b:

$ lsfrom --after b/
B
C

Equivalently the files from B:

$ echo $(lsfrom --from B)
B C

We can also list until:

$ lsfrom --until B
A
b
B

Note the file (collation) order will depend on the locale in general:

$ LC_COLLATE=C echo $(lsfrom -f B)
B C b

--from/--after can be combined with --until/--before. Without any of these options, the output should be similar to ls -A, but only 1 file per line.

The file of the path given does not need to exist (unless using --strict mode):

$ lsfrom -a /t
/tmp
/usr
/var

It is also possible to filter the listing with --dirs or --files.

A common use-case is continuing a program or script on the entries of a directory after a failure, etc:

$ myscript.sh $(lsfrom -f next)

or only running a command on a subrange of files or dirs in a directory.

Usage

$ lsfrom --version

2.0

$ lsfrom -h

List directories files starting from file

Usage: lsfrom [--version] [-s|--strict] [-A|--all] [--dirs | --files]
              [(-f|--from STARTFILE) | (-a|--after STARTFILE)]
              [(-u|--until LASTFILE) | (-b|--before LASTFILE)]

  lsfrom lists the files in a directory that follow from the given file

Available options:
  -h,--help                Show this help text
  --version                Show version
  -s,--strict              fail if specified file(s) do not exist
  -A,--all                 include hidden (dot) files
  --dirs                   Only list directories
  --files                  Only list files
  -f,--from STARTFILE      files from STARTFILE
  -a,--after STARTFILE     files after STARTFILE
  -u,--until LASTFILE      files until LASTFILE
  -b,--before LASTFILE     files before LASTFILE

Requirements

Tested on Linux (may also work on MacOS): specifically it uses libc collation (wcscoll()) for file ordering.

It also uses ls to list files sorted in the locale collation with the -A option to exclude ./ and ../ (ie coreutils).

Installation

stack install lsfrom or cabal install lsfrom.

Contribute or feedback

lsfrom is distributed with BSD license and the project is hosted at https://github.com/juhp/lsfrom.