Odd string formatting results for output file names...

[GeeMack]

Using IM 7.0.5-0 on Windows 10 64.

I start by making an animated GIF just to use as an example of a multi-layer image with this command...

Code: Select all

magick rose: -duplicate 5 -virtual-pixel tile ^
   -distort affine "0,0 0,%[fx:t*h/n]" -set delay 50 -loop 0 animrose.gif

Then I convert that "animrose.gif" into PNG files from the separate layers like this...

Code: Select all

magick animrose.gif -set filename:f "%[t]_" %[filename:f]%02d.png"

This creates the six images I'd expect, but the file names have done something funny...

Code: Select all

animrose_%02d00.png
animrose_%02d01.png
animrose_%02d02.png
animrose_%02d03.png
animrose_%02d04.png
animrose_%02d05.png

The files get numbered and padded to two places with leading zeroes, but the string formatting code "%02d" is still in there as part of the file name.

If I run the same command but put that underscore in the output file name at the end instead of in the "-set filename:f" like this...

Code: Select all

magick animrose.gif -set filename:f "%[t]" %[filename:f]_%02d.png"

I get an even stranger result...

Code: Select all

animrose_%02d.00.png
animrose_%02d.01.png
animrose_%02d.02.png
animrose_%02d.03.png
animrose_%02d.04.png
animrose_%02d.05.png

The filenames obtain an extra dot "." before the sequence numbers.

These discrepancies seem to behave differently when using different input and/or output file formats, too. If I start with this multi-layer TIF...

Code: Select all

magick rose: -duplicate 5 -virtual-pixel tile -distort affine "0,0 0,%[fx:t*h/n]" multirose.tif

... and run essentially the same command as above that inserted the extra dots "." in the filenames, those dots don't appear...

Code: Select all

multirose_%02d00.png
multirose_%02d01.png
multirose_%02d02.png
multirose_%02d03.png
multirose_%02d04.png
multirose_%02d05.png

And if I make the rose into a multipage PDF...

Code: Select all

magick rose: -duplicate 5 -virtual-pixel tile -distort affine "0,0 0,%[fx:t*h/n]" pdfrose.pdf

... and run it through this command...

Code: Select all

magick pdfrose.pdf -set filename:f "%[t]" %[filename:f]_%02d.jpg"

... it actually inserts an extra "j" and the extra dot "." in each filename. So that's weird.

Code: Select all

pdfrose_%02d.j00.jpg
pdfrose_%02d.j01.jpg
pdfrose_%02d.j02.jpg
pdfrose_%02d.j03.jpg
pdfrose_%02d.j04.jpg
pdfrose_%02d.j05.jpg

Now it could be using this sort of string formatting for output file names is undefined behavior when mixing it with "%[filename:f]", and maybe I shouldn't expect it to work at all. But if any of the combinations above are supposed to produce sequentially numbered output file names according to the string formatting "%02d", something isn't quite right. Any ideas?

[fmw42]

You have only 3 quotes rather than 4. However, that does not seem to make a difference for me.

[snibgo]

I assume you ran these at the command line, not in a BAT file?

... something isn't quite right. Any ideas?"

Agreed, testing with v6.9.5-3 and v7.0.3-5.

A workaround is to do all the string processing in the "-set filename", eg:

Code: Select all

convert animrose.gif -set filename:f "%[t]_%[s]" %[filename:f].png

But we can't then get leading zeroes.

[GeeMack]

I assume you ran these at the command line, not in a BAT file?

That is correct, yes.

But we can't then get leading zeroes.

Ay, there's the rub.

[GeeMack]

You have only 3 quotes rather than 4. However, that does not seem to make a difference for me.

Yep. That'd be a mistake typing the command in my haste. I can't recall the exact combination I used, but one attempt actually generated filenames with two extension, like "outfile_%02d00.jpg.jpg". Unexpected results in any case.

[GeeMack]

A couple more tests of input and output file names. I copied the PDF above to a new file named "pdf_rose_6pages.pdf". This command...

Code: Select all

magick pdf_rose_6pages.pdf -set filename:f "%[t]_" "%[filename:f]%02d.jpg"

... creates these files with part of the original name truncated...

Code: Select all

pdf_rose_6pag00.jpg
pdf_rose_6pag01.jpg
pdf_rose_6pag02.jpg
pdf_rose_6pag03.jpg
pdf_rose_6pag04.jpg
pdf_rose_6pag05.jpg

Copying the original 6 page PDF to a file named "p.pdf" and running this command...

Code: Select all

magick p.pdf -set filename:f "%[t]" "%[filename:f]_%02d.jpg"

... results in a single output file named "p_%02d.jpg.jpg". Interesting. It may be more related to the length of the file names than with the image format of the input/output files.