lsseq 3.0.1

ls-like command for image-sequences

About lsseq

lsseq is a Unix/Linux/MacOS command-line utility that lists directory contents like /bin/ls with the difference that lsseq condenses image and cache sequences to one entry each.

Filenames that are part of sequences are assumed to be of the form:

    <descriptiveName>.<frameNum>.<imgExtension>

where <imgExtension> is drawn from a comprehensive list of image extensions, or from a user supplied environment variable. lsseq also handles the case when the separator between the <descriptiveName> and the <frameNum> is an underscore instead of a dot.

lsseq first lists all non-image-sequence files followed by the list of image sequences as such:

    $ lsseq
    [output of /bin/ls minus image sequences]
    [list of images sequences]

Example:

    $ ls
    aaa.097.tif  aaa.100.tif  aaa.102.tif  bar.pdf
    aaa.098.tif  aaa.101.tif  aaa.103.tif  foo.txt
    $ lsseq
    bar.pdf  foo.txt
    aaa.[097-103].tif m:[99]

What lsseq tells us here is that this directory contains two non-image files, bar.pdf and foo.txt, plus a sequence of tif files named aaa with frames 97 through 103 (three padded) and frame 99 is missing.

lsseq prints sequences in its own native format, which is nice to read, however it can print sequences in a variety of formats useful for nuke, houdini or rv as well as a glob pattern for use in the shell.

Example:

    $ ls
    bbb.097.jpg  bbb.099.jpg  bbb.101.jpg  bbb.103.jpg
    bbb.098.jpg  bbb.100.jpg  bbb.102.jpg
    $ lsseq
    bbb.[097-103].jpg
    $ lsseq --format rv
    bbb.97-103@@@.jpg
    $ rv `lsseq -f rv`
    <rv launches with sequence bbb>
    $ rv -f nuke
    bbb.%03d.jpg 97-103
    $ lsseq -f glob
    bbb.[0-9][0-9][0-9].jpg

Installing lsseq

    python3 -m pip install lsseq

If you already have lsseq installed, upgrade to newer versions like this:

    python3 -m pip install lsseq --upgrade

There is additional installation-information below in an addendum with a helpful technique for installing lsseq system-wide.

Testing installation

To test lsseq, cd into a directory containing frames from an image sequence then lsseq the contents of the directory.

If you don't have one handy you can try this to test it.

    $ cd ~
    $ mkdir tmp
    $ cd tmp
    $ touch aaa.001.tif aaa.002.tif aaa.003.tif aaa.004.tif aaa.005.tif
    $ lsseq
    aaa.[001-005].tif z:[1-5]

Note the z:[1-5] which is telling you that the frames aaa.[001-005].tif have zero length.

Deeper dive on lsseq capabilities

lsseq was written to be as robust as possible. For example, it handles negative frames properly and has been extensively tested and used at several production studios for many years.

Furthermore, to ensure that updates to lsseq don't introduce new bugs, the lsseq repo contains extensive regression tests that are run and passed before every new release.

Why use lsseq?

Anyone who generates or works with frames of images for film and video needs lsseq. If not already using lsseq, then all major post-production studios have some kind of version of this essential tool. However I believe that lsseq is quintessential.

lsseq reports useful information in a nice compact form

Even if you aren't an avid command-line user, having lsseq available to you might make you a convert because it reports VERY useful information about sequences that are otherwise hard to discover without using lsseq.

Example:

    $ ls
    ccc_v01.0995.exr  ccc_v01.1029.exr  ccc_v02.1019.exr  ccc_v03.1008.exr
    ccc_v01.0996.exr  ccc_v01.1030.exr  ccc_v02.1020.exr  ccc_v03.1009.exr
    ccc_v01.0997.exr  ccc_v01.1031.exr  ccc_v02.1021.exr  ccc_v03.1010.exr
    ccc_v01.0998.exr  ccc_v01.1032.exr  ccc_v02.1022.exr  ccc_v03.1011.exr
    ccc_v01.1000.exr  ccc_v01.1033.exr  ccc_v02.1023.exr  ccc_v03.1012.exr
    ccc_v01.1001.exr  ccc_v01.1034.exr  ccc_v02.1024.exr  ccc_v03.1013.exr
    ccc_v01.1002.exr  ccc_v01.1035.exr  ccc_v02.1025.exr  ccc_v03.1014.exr
    ccc_v01.1003.exr  ccc_v02.0995.exr  ccc_v02.1026.exr  ccc_v03.1015.exr
    ccc_v01.1004.exr  ccc_v02.0996.exr  ccc_v02.1027.exr  ccc_v03.1016.exr
    ccc_v01.1005.exr  ccc_v02.0997.exr  ccc_v02.1028.exr  ccc_v03.1017.exr
    ccc_v01.1006.exr  ccc_v02.0998.exr  ccc_v02.1029.exr  ccc_v03.1018.exr
    ccc_v01.1007.exr  ccc_v02.0999.exr  ccc_v02.1030.exr  ccc_v03.1019.exr
    ccc_v01.1008.exr  ccc_v02.1000.exr  ccc_v02.1031.exr  ccc_v03.1020.exr
    ccc_v01.1009.exr  ccc_v02.1001.exr  ccc_v02.1032.exr  ccc_v03.1021.exr
    ccc_v01.1010.exr  ccc_v02.1002.exr  ccc_v02.1033.exr  ccc_v03.1022.exr
    ccc_v01.1011.exr  ccc_v02.1003.exr  ccc_v02.1034.exr  ccc_v03.1023.exr
    ccc_v01.1012.exr  ccc_v02.1004.exr  ccc_v02.1035.exr  ccc_v03.1024.exr
    ccc_v01.1013.exr  ccc_v02.1005.exr  ccc_v03.0995.exr  ccc_v03.1025.exr
    ccc_v01.1014.exr  ccc_v02.1006.exr  ccc_v03.0996.exr  ccc_v03.1026.exr
    ccc_v01.1015.exr  ccc_v02.1007.exr  ccc_v03.0997.exr  ccc_v03.1027.exr
    ccc_v01.1016.exr  ccc_v02.1008.exr  ccc_v03.0998.exr  ccc_v03.1028.exr
    ccc_v01.1017.exr  ccc_v02.1009.exr  ccc_v03.0999.exr  ccc_v03.1029.exr
    ccc_v01.1018.exr  ccc_v02.1010.exr  ccc_v03.1000.exr  ccc_v03.1030.exr
    ccc_v01.1019.exr  ccc_v02.1011.exr  ccc_v03.1001.exr  ccc_v03.1031.exr
    ccc_v01.1020.exr  ccc_v02.1012.exr  ccc_v03.1002.exr  ccc_v03.1032.exr
    ccc_v01.1021.exr  ccc_v02.1013.exr  ccc_v03.1003.exr  ccc_v03.1033.exr
    ccc_v01.1025.exr  ccc_v02.1014.exr  ccc_v03.1004.exr  ccc_v03.1034.exr
    ccc_v01.1026.exr  ccc_v02.1015.exr  ccc_v03.1005.exr  ccc_v03.1035.exr
    ccc_v01.1027.exr  ccc_v02.1016.exr  ccc_v03.1006.exr
    ccc_v01.1028.exr  ccc_v02.1018.exr  ccc_v03.1007.exr

    $ lsseq
    ccc_v01.[0995-1035].exr m:[999,1022-1024], z:[1030-1033]
    ccc_v02.[0995-1035].exr m:[1017]
    ccc_v03.[0995-1035].exr

This is a typical example of how hard it is to look at the contents of a directory containing image sequences without lsseq.

It's tough to spot that frames 999 and 1022-1024 are missing from v01 of the sequence, and frame 1017 is missing from v02. Furthermore, without doing a long listing (i.e. "ls -l"), you might miss that frames 1030-1033 of v01 are also zero length and empty. Maybe a bad render?

As you can see above, that information easily pops out when using lsseq.

If you like, you can turn off reporting zero-length and missing frames with some command-line options:

    $ lsseq --skipMissing --skipZero
    ccc_v01.[0995-1035].exr
    ccc_v02.[0995-1035].exr
    ccc_v03.[0995-1035].exr

lsseq is a natural partner to /bin/ls

lsseq is designed to have the flavor of the Unix/Linux/MacOS ls command as much as possible. The idea is to make it easier on the user when switching back and forth between using lsseq and regular ls so that the look of the output as well as several command-line-arguments are the same (where possible and makes sense).

The following example shows the similarity between the two commands. Command #1 and #2 below call /bin/ls on a sample directory. Then command #3 calls lsseq with the same wildcard as #2:

    1$ ls -F
    aaa/  bbb/  ccc.0101.exr  nonImage.file

    2$ ls *
    ccc.0101.exr  nonImage.file

    aaa:
    aaa.097.tif  aaa.100.tif  aaa.102.tif  nonImage_A.file
    aaa.098.tif  aaa.101.tif  aaa.103.tif

    bbb:
    bbx.0097.tif  bbx.0101.tif  bby.0198.tif  bby.0202.tif
    bbx.0098.tif  bbx.0102.tif  bby.0199.tif  bby.0203.tif
    bbx.0099.tif  bbx.0103.tif  bby.0200.tif  nonImage_B1.file
    bbx.0100.tif  bby.0197.tif  bby.0201.tif  nonImage_B2.file

    3$ lsseq *
    nonImage.file
    ccc.[0101].exr

    aaa:
    nonImage_A.file
    aaa.[097-103].tif m:[99]

    bbb:
    nonImage_B1.file  nonImage_B2.file
    bbx.[0097-0103].tif
    bby.[0197-0203].tif

The first thing to note above is how close lsseq is to mimicking /bin/ls in labelling directories and listing directory contents etc. (compare the output of command #2 to #3). The difference being that lsseq first lists all non-sequence images in a directory exactly as ls would list them (minus the sequences) then lists all the sequences in their condensed form.

Natural extension of lsseq beyond /bin/ls

Some useful options have been added, beyond what /bin/ls does, that extend lsseq's capability.

    4$ lsseq --prependPathRel *
    ccc.[0101].exr
    aaa/aaa.[097-103].tif m:[99]
    bbb/bbx.[0097-0103].tif
    bbb/bby.[0197-0203].tif

    5$ lsseq --prependPathAbs --skipMissing --format rv *
    /user/jrowellfx/test/ccc.0101.exr
    /user/jrowellfx/test/aaa/aaa.97-103@@@.tif
    /user/jrowellfx/test/bbb/bbx.97-103#.tif
    /user/jrowellfx/test/bbb/bby.197-203#.tif

Continuing in our sample directory from the previous example, note the two options in commands #4 and #5, namely --prependPathRel and --prependPathAbs. These are both useful when creating lists of sequences to pipe into other scripts.

Sorting by modification times

/bin/ls allows us to sort directory contents by modification time as well as by filename. lsseq also duplicates this functionality but adds options to specify which frame from each sequence to use when comparing modification times. You can compare sequences by comparing the oldest, median or newest frames from each sequence with the --time FRAME_AGE option.

lsseq can also limit listing sequences that are created before or after a given timestamp with the --onlyShow TENSE [CC]YYMMDD[-hh[mm[ss]]] option, where TENSE is either before or since.

An especially powerful feature of lsseq is the ability to sort by time across different directories. This is special to lsseq as /bin/ls doesn't sort by time across directories. Here's how you do it with lsseq, the description snipped from the output of lsseq --help:

  --globalSortByTime    when using either --prependPathAbs or --prependPathRel
                        then this option will sort ALL sequences by time
                        compared to each other, as opposed to only sorting
                        sequences by time within their common directory. If
                        the above conditions are NOT met, then this option is
                        simply ignored.

Please explore the rest of lsseq's capabilities by typing:

    $ lsseq --help

Error codes returned by lsseq

As copied from the source code, the following EXIT codes will be combined bitwise to return possibly more than one different warning and/or error.

EXIT_NO_ERROR               = 0 # Clean exit.
EXIT_LS_ERROR               = 1 # A call to 'ls' returned an error code.
EXIT_ARGPARSE_ERROR         = 2 # A bad option was passed to lsseq. Exit lsseq.
EXIT_LSSEQ_SOFTLINK_WARNING = 4 # warning - broken softlink found
EXIT_LSSEQ_PADDING_WARNING  = 8 # warning - two images with same name, same frame-num, but diff padding

Addendum - more on installing command-line tools

Here's the process that I've followed to install lsseq, as well as my other python-based command-line tools (i.e., renumseq, expandseq, condenseseq and fixSeqPadding) so that they are accessible to all users. This works on both MacOS and Linux.

    $ su -
    # cd /usr/local
    # python3 -m venv venv
    # cd venv
    # source bin/activate
    # python3 -m pip install --upgrade pip
    # deactivate
    # bin/pip install lsseq
    # bin/pip install expandSeq
    # bin/pip install renumSeq
    # bin/pip install fixSeqPadding
    # ln -s /usr/local/venv/bin/lsseq /usr/local/bin/lsseq
    # ln -s /usr/local/venv/bin/expandseq /usr/local/bin/expandseq
    # ln -s /usr/local/venv/bin/condenseseq /usr/local/bin/condenseseq
    # ln -s /usr/local/venv/bin/renumseq /usr/local/bin/renumseq
    # ln -s /usr/local/venv/bin/fixseqpadding /usr/local/bin/fixseqpadding
    # exit
    $ lsseq --version
    3.0.1

At this point any user should be able to run any of the commands linked in the example above. Note that updates are easy now too. Say there's an update to lsseq that you want to install.

    $ su -
    # cd /usr/local/venv
    # bin/pip install lsseq --upgrade
    # exit
    $ lsseq --version
    99.99.99

Just kidding about the version number, maybe in the year 2159? Will Unix still be a thing!?

Helpful hint: Upgraded the system-wide default version of python3?

Say you had installed lsseq as described above, while the default python3 was linked to python3.6. Then suppose the system default python3 was then linked to a higher version of python (Check with: python3 --version). At that point running lsseq might error out like this:

Traceback (most recent call last):
  File "/usr/local/bin/lsseq", line 5, in <module>
    from lsseq.__main__ import main
ModuleNotFoundError: No module named 'lsseq'

This is an easy problem to fix. Delete (or move to a backup location) the entire directory /usr/local/venv and redo the steps above to install lsseq, renumseq, expandseq etc. from scratch.

Contact

Please contact j a m e s <at> a l p h a - e l e v e n . c o m with any bug reports, suggestions or praise as the case may be.