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Re: how to convert 100 bmp files to jpeg?

Tim Connors wrote:



Nope -- heaps of people have done this before you.  Did you pick this
technique up from someone else?

It'd be nice if the technique would kindly stop propogating :)
Well, I believe I got this from some "advanced" bash guide, or a man page or two. 


<snip>

I don't think there is a fixed limit glob buffer.  Are you sure you
are not confusing this with the amount of space bash is allowed to
allocate for arguments for spawned commands -- a kernel limit?

All I know is that it works for me.


So saying:
for a in * ; do
  blah "$a"
done
has no limit, whereas
blah2 *
does have a limit (of about 20K characters, IIRC).

(hmmm, maybe more on the 2.6 kernel -- I can't seem to generate that
dreaded "Argument list too long" message except by doing something
stupid like:   ls -lA /var/spool/news/message.id/*/*   )
I have run into this message many times - but I manage a fileserver that has several million files. Naturally, I try to really avoid any sort of manipulation on this server, but sometimes there is no way it can be avoided. (From memory, I had to use find, rather than ls) 


And imho, much easier than dealing with xargs and find -exec whatnot ;
Also, if spaces are a problem, fancy quotes can deal with that:
for f in `ls *.bmp`; do echo "$f"; done <-- Note I have NOT tested this.


Nope.

#mkdir tmp
#cd tmp
#for i in `seq 1 10000` ; do touch "blah $i" ; done
#for f in `ls *`; do ls -lA "$f"; done
ls: blah: No such file or directory
ls: 1: No such file or directory
ls: blah: No such file or directory
ls: 10: No such file or directory
ls: blah: No such file or directory
ls: 100: No such file or directory
ls: blah: No such file or directory
ls: 1000: No such file or directory
ls: blah: No such file or directory
....

Because each space output by the backticks causes the for loop to plop
the next bit into a new loop.

Interesting.
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