Re: eps to jpg conversion - which program?
On Sat, 8 Nov 2008 23:36:32 -0800, Jeremy Chadwick <[EMAIL PROTECTED]> wrote: > Also, what guarantee do you have that all the filenames that match that > wildcard lack spaces in them? Your [ and convert commands will botch > badly in that case. See below. This is completely correct. If files are present as foo.EPS, the "Windows" style of file naming, or foo.Eps in a mixed form, the *.eps wouldn't catch it. As you mentioned, it's good to assume the worst case. Not only spaces, as well special characters. Now *that's* the real fun. :-) [EMAIL PROTECTED] sent me | Copy [5] of C:\My Files\A&V with ö and ß.Eps Another mentionable comment would be: "Why do you call the variable just $f? Give it a better descriptive name." In this small example, it won't lead into significant problems if you don't do it, but I've seen shellscripts using $f, $f1, $f2, $g, $h, $y all over the file, and it was hard to find out which values they should hold. > > What people often forget while writing sh scripts is that spawning > external utilities slows down the script greatly, and destroys system > resources. You might think "My machine has 923484390GB of RAM, and has > 6500 processors; why do I care?" -- step back for a moment and think > about older/smaller boxes, or even more importantly, embedded machines > (very little memory, very little CPU). Hey, that's how software development helps hardware development, or at least software development in Redmond. :-) Hardware ressources ++ Overall usage speed = = const. Software requirements ++ q.e.d. > Also think about situations where fork() will fail due to resource > limits or existing system resource exhaustion; what then? I see this > regularly in perl scripts; people relying on `xxx` for no good reason. > I ask them, "Why are you doing this? Can you not use > instead, and avoid wasting resources and excessive risk?", and they > often have no idea what I'm talking about. And whenever I see `ssh > [EMAIL PROTECTED] "command"` in perl scripts, I cry. Ooow! Is this for real? If it is, it's a reason to hit someone's head with the keyboard. :-) > That in mind, don't let your scripting mimic that of "perl bastards" who > *intentionally* write obfuscated code just to "show off" (often citing > "its faster" as the reason, choosing to intentionally ignore that perl > is a compiled language). For complex pieces of sh that are hard to > visually parse: try to keep it simple, and take the time to write > decent/legible comments above the hairy part of the script. Indentation, comments and descriptive identifiers help a lot. If you read FreeBSD's (scripting) sources, you'll see that they are of high quality. > Also remember that double-quoting filenames or variables that are used > as filenames is a VERY good idea. Filenames with spaces are quite > common these days. It's best to assume the worst, but not be *too* > over-zealous. Especially when you're intending to use a piece of software, even if it's just a three line shell script, more than just one time, or if you want to share it with others. -- Polytropon >From Magdeburg, Germany Happy FreeBSD user since 4.0 Andra moi ennepe, Mousa, ... ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: eps to jpg conversion - which program?
On Sun, Nov 09, 2008 at 07:25:49AM +0100, Polytropon wrote:
> On Sat, 8 Nov 2008 12:12:46 +0200, Jonathan McKeown <[EMAIL PROTECTED]> wrote:
> > Essentially, a Bourne-type shell with parameter expansion expands
> > ${variable#prefix} or ${variable%suffix} to $variable with the prefix or
> > suffix, respectively, removed.
>
> So this would be more efficient:
>
> #!/bin/sh
> for f in *eps; do
> [ ! -f ${f%.eps}.jpg ] && convert $f ${f%.eps}.jpg
> done
Significantly.
Also, what guarantee do you have that all the filenames that match that
wildcard lack spaces in them? Your [ and convert commands will botch
badly in that case. See below.
What people often forget while writing sh scripts is that spawning
external utilities slows down the script greatly, and destroys system
resources. You might think "My machine has 923484390GB of RAM, and has
6500 processors; why do I care?" -- step back for a moment and think
about older/smaller boxes, or even more importantly, embedded machines
(very little memory, very little CPU).
Also think about situations where fork() will fail due to resource
limits or existing system resource exhaustion; what then? I see this
regularly in perl scripts; people relying on `xxx` for no good reason.
I ask them, "Why are you doing this? Can you not use
instead, and avoid wasting resources and excessive risk?", and they
often have no idea what I'm talking about. And whenever I see `ssh
[EMAIL PROTECTED] "command"` in perl scripts, I cry.
That in mind, don't let your scripting mimic that of "perl bastards" who
*intentionally* write obfuscated code just to "show off" (often citing
"its faster" as the reason, choosing to intentionally ignore that perl
is a compiled language). For complex pieces of sh that are hard to
visually parse: try to keep it simple, and take the time to write
decent/legible comments above the hairy part of the script.
Also remember that double-quoting filenames or variables that are used
as filenames is a VERY good idea. Filenames with spaces are quite
common these days. It's best to assume the worst, but not be *too*
over-zealous.
And don't forget about "set noglob" when appropriate!
--
| Jeremy Chadwickjdc at parodius.com |
| Parodius Networking http://www.parodius.com/ |
| UNIX Systems Administrator Mountain View, CA, USA |
| Making life hard for others since 1977. PGP: 4BD6C0CB |
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Re: eps to jpg conversion - which program?
On Sat, 8 Nov 2008 12:12:46 +0200, Jonathan McKeown <[EMAIL PROTECTED]> wrote:
> You can also save yourself repeated calls to basename by using
>
> for f in *eps; do
> convert ${f%.eps}.jpg
> done
>
> Look under parameter expansion in the manpage for sh(1) (or bash(1) if you
> have bash installed).
Yes, that's a very good hint, I will use this in the future.
Note that $f as first parameter is missing (source for convert).
> As far as I can tell csh/tcsh doesn't support this
> useful feature.
Well, I prefer the C Shell (instead of BASH) as primary dialog shell,
but for scripting, I always stay with the "good old" Bourne Shell,
simply because it's the standard scripting shell for UNIX, and it's
compatible to most Linusi, too (where /bin/sh@ -> /bin/bash,
but NB ! -f /bin/bash in FreeBSD).
> Essentially, a Bourne-type shell with parameter expansion expands
> ${variable#prefix} or ${variable%suffix} to $variable with the prefix or
> suffix, respectively, removed.
So this would be more efficient:
#!/bin/sh
for f in *eps; do
[ ! -f ${f%.eps}.jpg ] && convert $f ${f%.eps}.jpg
done
--
Polytropon
>From Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...
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Re: eps to jpg conversion - which program?
On Friday 07 November 2008 21:19, Polytropon wrote:
> On Fri, 07 Nov 2008 13:36:51 +0100, Laszlo Nagy <[EMAIL PROTECTED]>
wrote:
> A batch solution is simple:
>
> #!/bin/sh
> for f in *eps; do
> convert ${f} `basename ${f} .eps`.jpg
> done
You can also save yourself repeated calls to basename by using
for f in *eps; do
convert ${f%.eps}.jpg
done
Look under parameter expansion in the manpage for sh(1) (or bash(1) if you
have bash installed). As far as I can tell csh/tcsh doesn't support this
useful feature.
Essentially, a Bourne-type shell with parameter expansion expands
${variable#prefix} or ${variable%suffix} to $variable with the prefix or
suffix, respectively, removed.
Jonathan
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Re: eps to jpg conversion - which program?
On Fri, 07 Nov 2008 13:36:51 +0100, Laszlo Nagy <[EMAIL PROTECTED]> wrote:
>
> Hi,
>
> I need to convert eps files into jpeg files in batch mode. Gimp works
> perfectly, except that I cannot use an X display. I tried eps2png with
> no success:
You can use the convert command from ImageMagick:
convert
A batch solution is simple:
#!/bin/sh
for f in *eps; do
convert ${f} `basename ${f} .eps`.jpg
done
You can add
[ ! -f `basename ${f} .eps`.jpg ] &&
infront of the convert command to avoid repeated conversions.
--
Polytropon
>From Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...
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Re: eps to jpg conversion - which program?
Laszlo Nagy schrieb: > I need to convert eps files into jpeg files in batch mode. Gimp works > perfectly, except that I cannot use an X display. I tried eps2png with > no success: > > > %file test.eps > test.eps: DOS EPS Binary File Postscript starts at byte 30 length 566887 > TIFF starts at byte 566917 length 4741 > %eps2png -jpg -width 1000 -verbose -output test.jpg test.eps > Producing jpg (jpeg) image. > Not EPS file: test.eps, skipped > > What port should I use to convert EPS into JPG? I would like to use a > program that shares the same library with Gimp, because we know that > Gimp works great for this task. Take a look on GhostScript, a PostScript interpreter. -- Timm ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: eps to jpg conversion - which program?
Laszlo Nagy wrote: Hi, I need to convert eps files into jpeg files in batch mode. Gimp works perfectly, except that I cannot use an X display. I tried eps2png with no success: %file test.eps test.eps: DOS EPS Binary File Postscript starts at byte 30 length 566887 TIFF starts at byte 566917 length 4741 %eps2png -jpg -width 1000 -verbose -output test.jpg test.eps Producing jpg (jpeg) image. Not EPS file: test.eps, skipped What port should I use to convert EPS into JPG? I would like to use a program that shares the same library with Gimp, because we know that Gimp works great for this task. Thanks, Laszlo How about using 'convert' from graphics/ImageMagick? It would be as simple as convert myfile.eps myfile.jpg and there are myriads of options to fiddle if you wish. I've been using it with great success for quite some time now. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
