I wonder if we aren't making too much of the memory gains. I tried running the vm_stat a few times in a row and found that the pages free can fluctuate quite a bit without doing anything (except running programs in the background)...

Batch operations in UNIX?
 

I think I found one place where memory is getting hogged and I have an idea about how to fix it, but I need UNIX help!

I tried to keep everything as simple as possible. First I changed my ImageMagick command to output mulitple PBM (portable bitmap) files instead of one single file.

Then, I restarted my machine and ran the command:

(This converts them to individual Tiff files with numbers output01.tif, output02.tif, etc.)

These PBM files are about 500K each, and after it went through 29 of the 59 files, I got this error:

For all the remaining files.

Now, what I realize in using +adjoin in ImageMagick is that it seems to first do all the conversions in memory (for all the files) and then to write them to disk afterwards!!! What I would like to know how to do is to tell ImageMagick to do this for one file at a time!

Something like:

For each file *.pbm
Convert to compressed Tiff
Renaming with the same name but changing the extension.

I imagine that there is a UNIX command for this but I don't know where to look - especially for the naming part!

TIA!

What about a simple foreach loop: that might start/stop imagemagick once per file, thus leaving lighter footprints.

% foreach file (*.pbm)
foreach? nice +10 convert -compress zip $file (etc etc)
foreach? end

Worth a go!

Cheers,
Paul

(You can of course throw this into a file --say "scriptname" with

#!/bin/sh

on the first line (and no "foreach?" on lines 2 and 3; the shell adds these in when you do this interactively), then make it executable and just use

./scriptname

to run it)

better use #!/bin/csh with foreach

sh no got foreach

sh has:

for NAME [in WORDS ... ;] do COMMANDS; done

for file in /path/to/*.pbm;
do
nice...;
done

Getting there!
 

Amazing. This is definately the way to go! It was much faster, and it did all the files without error.

I want to sort out one more thing before I go trying to write a script for this (I'm still doing it manually), and that is get the process of file naming using the "foreach" command down. I tried reading the man (I really did), but what I came up with is this and it doesn't work:

If the original file was file01.pbm, the output file should be file01.tif, but I get: "file01.pbm.tif" instead. I though the :h would strip the tail leaving only the header, but I guess I misunderstood the manual.

Thanks.

Re: Getting there!
 

Try replacing $file:h.tiff by "`basename $file .pbm`.tif"

And yes, that is a space after $file. (Is it '.tif' you want or '.tiff'? You say both :-) )

hth

Great. In another thread someone suggested "basename" but I didn't notice that it required a space. Now it works! Such small things. Thanks about the tif/tiff thing too. Doesn't really matter as far as I can tell, but it is good to be consistent!

Now the question is how to get this script to work not on the top level folder, but for all the sub-folders in it. That is, I have a folder called "scans" and it contains multiple folders "scanfolder 1" "scanfolder 2" etc. How do I get the script to operate on the TIF files inside each of these folders, rather than just the top level?

I'm also having a problem with this code not accepting directories with spaces in the name, even if they are input in quotes or with backslashes or even both ...

Full script (but problems remain)
 

I haven't solved the issues from my last post, but here is the full script as it now stands:

[edit: readability -mt]

Got it! (Almost)
 

I finally got the recursive directory thing! Now I just need to figure out why it isn't accepting spaces in directory paths...

Here is the final script. All I intend to do now is fix some of the feedback, and set it to work with fixed top-level directories. I want to have one directory called "portrait" and one called "landscape" - that way I can simply save scans to the appropriate directory and the script will treate them each correctly. When done I will post back here. But for now, this is what I have:

[edit: readability -mt]

would this make sense if you run du on a system that seems to become sluggish to avoid a crash? I mean if you catch it early enough?

although not a unix solution, I just deleted my loginwindow plist files and the system seems to be handling memory much better.