#44 Windows binaries using wrong slash in output filename

[Anonymous]

Problem: The Windows binaries sometimes use a forward slash instead of a back slash in the output filename, which generates an error, but pngcrush writes a very large PNG file to the output filename anyway, which is annoying behavior, because it actually makes files that are larger than the original.

Expected outcome: Pngcrush should use only backslashes in the filename on Windows platforms, and it should not write larger files than the original if a filesystem error occurs.

Terminal output: (notice the forward slash in the error message "Could not open output file")

C:\Users\admin\folder>C:\Users\admin\pngcrush.exe -d "C:\
Users\admin\folder_crush" -bit_depth 1 -plte_len 1 -brute -w 32 -
c 0 "C:\Users\admin\folder\image0009.png"

| pngcrush 1.7.15
| Copyright (C) 1998-2002,2006-2011 Glenn Randers-Pehrson
| Portions copyright (C) 2005 Greg Roelofs
| This is a free, open-source program. Permission is irrevocably
| granted to everyone to use this version of pngcrush without
| payment of any fee.
| Executable name is pngcrush
| It was built with libpng version 1.5.2rc02, and is
| running with libpng version 1.5.2rc02 - March 22, 2011

| Copyright (C) 1998-2004, 2006-2011 Glenn Randers-Pehrson,
| Copyright (C) 1996, 1997 Andreas Dilger,
| Copyright (C) 1995, Guy Eric Schalnat, Group 42 Inc.,
| and zlib version 1.2.5, Copyright (C) 1995-2010 (or later),
| Jean-loup Gailly and Mark Adler.
| It was compiled with gcc version 4.5.2.

Recompressing C:\Users\admin\folder\image0009.png
Total length of data found in IDAT chunks = 2032
Reducing truecolor image to grayscale.
IDAT length with method 11 (fm 0 zl 2 zs 2) = 86749
IDAT length with method 12 (fm 1 zl 2 zs 2) = 86856
Could not open output file C:\Users\admin\folder_crush/image000
9.png

[Glenn Randers-Pehrson]

Thanks. I think this failure only occurs when the "-d" option is used, and the binary is built not with DJGPP as was the case in the past. I have revised pngcrush-1.7.23 to use the backslash on Windows platforms. Sorry, I don't have access to a Windows development platform so can't make or test the binary. I have uploaded sources.

[Anonymous]

I tried to compile it under Cygwin, and I ran it under cmd.exe. It's still giving the error randomly on some image files.

Output:
C:\Users\admin\folder>C:\Users\admin\pngcrush.exe -d "C:\
Users\Oak\Downloads\folder_crush" -bit_depth 1 -plte_len 1 -brute -w 32 -
c 0 "C:\Users\admin\folder\folder0006.png"

| pngcrush 1.7.23
| Copyright (C) 1998-2002,2006-2012 Glenn Randers-Pehrson
| Portions copyright (C) 2005 Greg Roelofs
| This is a free, open-source program. Permission is irrevocably
| granted to everyone to use this version of pngcrush without
| payment of any fee.
| Executable name is pngcrush
| It was built with libpng version 1.5.7, and is
| running with libpng version 1.5.7 - December 15, 2011

| Copyright (C) 1998-2004, 2006-2012 Glenn Randers-Pehrson,
| Copyright (C) 1996, 1997 Andreas Dilger,
| Copyright (C) 1995, Guy Eric Schalnat, Group 42 Inc.,
| and zlib version 1.2.5, Copyright (C) 1995-2010 (or later),
| Jean-loup Gailly and Mark Adler.
| It was compiled with gcc version 3.4.4 (cygming special, gdc 0.12, using dmd
0.125).

cygwin warning:
MS-DOS style path detected: C:\Users\admin\folder_crush
Preferred POSIX equivalent is: /admin/folder_crush
CYGWIN environment variable option "nodosfilewarning" turns off this warning.
Consult the user's guide for more details about POSIX paths:
http://cygwin.com/cygwin-ug-net/using.html#using-pathnames
Recompressing C:\Users\admin\folder\folder0006.png
Total length of data found in IDAT chunks = 2032
Reducing truecolor image to grayscale.
IDAT length with method 11 (fm 0 zl 2 zs 2) = 86749
IDAT length with method 12 (fm 1 zl 2 zs 2) = 86856
IDAT length with method 13 (fm 2 zl 2 zs 2) = 86870
IDAT length with method 14 (fm 3 zl 2 zs 2) = 86875
IDAT length with method 15 (fm 4 zl 2 zs 2) = 86878
IDAT length with method 16 (fm 5 zl 2 zs 2) = 86749
IDAT length with method 17 (fm 0 zl 1 zs 0) = 3040
IDAT length with method 18 (fm 1 zl 1 zs 0) = 4390
IDAT length with method 19 (fm 2 zl 1 zs 0) = 4390
IDAT length with method 20 (fm 3 zl 1 zs 0) = 4390
IDAT length with method 21 (fm 4 zl 1 zs 0) = 4391
IDAT length with method 22 (fm 5 zl 1 zs 0) = 3040
IDAT length with method 23 (fm 0 zl 1 zs 1) = 3040
IDAT length with method 24 (fm 1 zl 1 zs 1) = 4390
IDAT length with method 25 (fm 2 zl 1 zs 1) = 4390
IDAT length with method 26 (fm 3 zl 1 zs 1) = 4390
IDAT length with method 27 (fm 4 zl 1 zs 1) = 4391
IDAT length with method 28 (fm 5 zl 1 zs 1) = 3040
Could not open output file C:\Users\admin\folder_crush\badappletr
ace0006.png

[Glenn Randers-Pehrson]

That's somewhat crazy. Cygwin reads filenames with backslashes but must have
forward slashes when it writes them. What about the C:\ Does that have to be
C/ or what?

Also it cannot be "random" but specifically when the "-d" option is used with
full pathnames.

[Glenn Randers-Pehrson]

Ah, I see, it wants the "C:\Users\" changed to "/" on a Cygwin platform.

[Glenn Randers-Pehrson]

Does this work (i.e. using a POSIX-style directory name in the -d option)?

C:\Users\admin\folder>C:\Users\admin\pngcrush.exe -d "/Oak/Downloads/folder_crush" -bit_depth 1 -plte_len 1 -brute -w 32 -
c 0 "C:\Users\admin\folder\folder0006.png"

[Anonymous]

I tried modifying my batch file somewhat so that it would work correctly under Cygwin.
When in Cygwin, the following line does not work, and it outputs an ~80kB file instead of a ~7kB file like I would expect.

$ /cygdrive/c/Users/Oak/Downloads/pngcrush.exe -d "/cygdrive/c/Users/Oak/Downlo
ads/badappletrace_crush" -bit_depth 1 -plte_len 1 -brute -w 32 -c 0 "/cygdrive/
c/Users/Oak/Downloads/badappletrace/badappletrace0799.png"

| pngcrush 1.7.23
| Copyright (C) 1998-2002,2006-2012 Glenn Randers-Pehrson
| Portions copyright (C) 2005 Greg Roelofs
| This is a free, open-source program. Permission is irrevocably
| granted to everyone to use this version of pngcrush without
| payment of any fee.
| Executable name is pngcrush
| It was built with libpng version 1.5.7, and is
| running with libpng version 1.5.7 - December 15, 2011

| Copyright (C) 1998-2004, 2006-2012 Glenn Randers-Pehrson,
| Copyright (C) 1996, 1997 Andreas Dilger,
| Copyright (C) 1995, Guy Eric Schalnat, Group 42 Inc.,
| and zlib version 1.2.5, Copyright (C) 1995-2010 (or later),
| Jean-loup Gailly and Mark Adler.
| It was compiled with gcc version 3.4.4 (cygming special, gdc 0.12, using dmd
0.125).

Recompressing /cygdrive/c/Users/Oak/Downloads/badappletrace/badappletrace0799
.png
Total length of data found in IDAT chunks = 7158
Reducing truecolor image to grayscale.
IDAT length with method 11 (fm 0 zl 2 zs 2) = 87682
IDAT length with method 12 (fm 1 zl 2 zs 2) = 87739
IDAT length with method 13 (fm 2 zl 2 zs 2) = 87332
Could not open output file /cygdrive/c/Users/Oak/Downloads/badappletrace_crush\b
adappletrace0799.png

[Glenn Randers-Pehrson]

Try pngcrush-1.7.24

The -d option now takes an optional slash, so if pngcrush is supplying
the wrong type on some platform, the user can supply the correct one, e.g.,

/cygdrive/c/Users/Oak/Downloads/pngcrush.exe -d
"/cygdrive/c/Users/Oak/Downloads/badappletrace_crush/" -bit_depth 1 -plte_len 1 -brute -w 32 -c 0
"/cygdrive/c/Users/Oak/Downloads/badappletrace/badappletrace0799.png"

[Anonymous]

I'm still getting the error, but the slash is facing the correct direction. Oddly enough, I ran the same command three times, and each time, the error occurs after a different "IDAT length with method" iteration, in a seemingly random way. Cygwin output is below:

$ /cygdrive/c/Users/Oak/Downloads/pngcrush.exe -d "/cygdrive/c/Users/Oak/Downlo
ads/badappletrace_crush/" -bit_depth 1 -plte_len 1 -brute -w 32 -c 0 "/cygdrive
/c/Users/Oak/Downloads/badappletrace/badappletrace0799.png"

| pngcrush 1.7.24
| Copyright (C) 1998-2002,2006-2012 Glenn Randers-Pehrson
| Portions copyright (C) 2005 Greg Roelofs
| This is a free, open-source program. Permission is irrevocably
| granted to everyone to use this version of pngcrush without
| payment of any fee.
| Executable name is pngcrush
| It was built with libpng version 1.5.7, and is
| running with libpng version 1.5.7 - December 15, 2011

| Copyright (C) 1998-2004, 2006-2012 Glenn Randers-Pehrson,
| Copyright (C) 1996, 1997 Andreas Dilger,
| Copyright (C) 1995, Guy Eric Schalnat, Group 42 Inc.,
| and zlib version 1.2.5, Copyright (C) 1995-2010 (or later),
| Jean-loup Gailly and Mark Adler.
| It was compiled with gcc version 3.4.4 (cygming special, gdc 0.12, using dmd
0.125).

Recompressing /cygdrive/c/Users/Oak/Downloads/badappletrace/badappletrace0799
.png
Total length of data found in IDAT chunks = 7158
Reducing truecolor image to grayscale.
IDAT length with method 11 (fm 0 zl 2 zs 2) = 87682
IDAT length with method 12 (fm 1 zl 2 zs 2) = 87739
IDAT length with method 13 (fm 2 zl 2 zs 2) = 87332
IDAT length with method 14 (fm 3 zl 2 zs 2) = 88421
IDAT length with method 15 (fm 4 zl 2 zs 2) = 87425
IDAT length with method 16 (fm 5 zl 2 zs 2) = 87314
Could not open output file /cygdrive/c/Users/Oak/Downloads/badappletrace_crush/b
adappletrace0799.png

$ /cygdrive/c/Users/Oak/Downloads/pngcrush.exe -d "/cygdrive/c/Users/Oak/Downlo
ads/badappletrace_crush/" -bit_depth 1 -plte_len 1 -brute -w 32 -c 0 "/cygdrive
/c/Users/Oak/Downloads/badappletrace/badappletrace0799.png"

| pngcrush 1.7.24
| Copyright (C) 1998-2002,2006-2012 Glenn Randers-Pehrson
| Portions copyright (C) 2005 Greg Roelofs
| This is a free, open-source program. Permission is irrevocably
| granted to everyone to use this version of pngcrush without
| payment of any fee.
| Executable name is pngcrush
| It was built with libpng version 1.5.7, and is
| running with libpng version 1.5.7 - December 15, 2011

| Copyright (C) 1998-2004, 2006-2012 Glenn Randers-Pehrson,
| Copyright (C) 1996, 1997 Andreas Dilger,
| Copyright (C) 1995, Guy Eric Schalnat, Group 42 Inc.,
| and zlib version 1.2.5, Copyright (C) 1995-2010 (or later),
| Jean-loup Gailly and Mark Adler.
| It was compiled with gcc version 3.4.4 (cygming special, gdc 0.12, using dmd
0.125).

Recompressing /cygdrive/c/Users/Oak/Downloads/badappletrace/badappletrace0799
.png
Total length of data found in IDAT chunks = 7158
Reducing truecolor image to grayscale.
IDAT length with method 11 (fm 0 zl 2 zs 2) = 87682
IDAT length with method 12 (fm 1 zl 2 zs 2) = 87739
IDAT length with method 13 (fm 2 zl 2 zs 2) = 87332
Could not open output file /cygdrive/c/Users/Oak/Downloads/badappletrace_crush/b
adappletrace0799.png

$ /cygdrive/c/Users/Oak/Downloads/pngcrush.exe -d "/cygdrive/c/Users/Oak/Downlo
ads/badappletrace_crush/" -bit_depth 1 -plte_len 1 -brute -w 32 -c 0 "/cygdrive
/c/Users/Oak/Downloads/badappletrace/badappletrace0799.png"

| pngcrush 1.7.24
| Copyright (C) 1998-2002,2006-2012 Glenn Randers-Pehrson
| Portions copyright (C) 2005 Greg Roelofs
| This is a free, open-source program. Permission is irrevocably
| granted to everyone to use this version of pngcrush without
| payment of any fee.
| Executable name is pngcrush
| It was built with libpng version 1.5.7, and is
| running with libpng version 1.5.7 - December 15, 2011

| Copyright (C) 1998-2004, 2006-2012 Glenn Randers-Pehrson,
| Copyright (C) 1996, 1997 Andreas Dilger,
| Copyright (C) 1995, Guy Eric Schalnat, Group 42 Inc.,
| and zlib version 1.2.5, Copyright (C) 1995-2010 (or later),
| Jean-loup Gailly and Mark Adler.
| It was compiled with gcc version 3.4.4 (cygming special, gdc 0.12, using dmd
0.125).

Recompressing /cygdrive/c/Users/Oak/Downloads/badappletrace/badappletrace0799
.png
Total length of data found in IDAT chunks = 7158
Reducing truecolor image to grayscale.
IDAT length with method 11 (fm 0 zl 2 zs 2) = 87682
IDAT length with method 12 (fm 1 zl 2 zs 2) = 87739
IDAT length with method 13 (fm 2 zl 2 zs 2) = 87332
IDAT length with method 14 (fm 3 zl 2 zs 2) = 88421
IDAT length with method 15 (fm 4 zl 2 zs 2) = 87425
IDAT length with method 16 (fm 5 zl 2 zs 2) = 87314
IDAT length with method 17 (fm 0 zl 1 zs 0) = 10123
IDAT length with method 18 (fm 1 zl 1 zs 0) = 11712
IDAT length with method 19 (fm 2 zl 1 zs 0) = 9905
IDAT length with method 20 (fm 3 zl 1 zs 0) = 13384
IDAT length with method 21 (fm 4 zl 1 zs 0) = 9657
IDAT length with method 22 (fm 5 zl 1 zs 0) = 9946
IDAT length with method 23 (fm 0 zl 1 zs 1) = 10123
IDAT length with method 24 (fm 1 zl 1 zs 1) = 11712
IDAT length with method 25 (fm 2 zl 1 zs 1) = 9905
IDAT length with method 26 (fm 3 zl 1 zs 1) = 13384
IDAT length with method 27 (fm 4 zl 1 zs 1) = 9657
IDAT length with method 28 (fm 5 zl 1 zs 1) = 9946
IDAT length with method 29 (fm 0 zl 2 zs 0) = 9486
IDAT length with method 30 (fm 1 zl 2 zs 0) = 10807
IDAT length with method 31 (fm 2 zl 2 zs 0) = 9593
IDAT length with method 32 (fm 3 zl 2 zs 0) = 12561
IDAT length with method 33 (fm 4 zl 2 zs 0) = 9390
IDAT length with method 34 (fm 5 zl 2 zs 0) = 9579
IDAT length with method 35 (fm 0 zl 2 zs 1) = 9486
IDAT length with method 36 (fm 1 zl 2 zs 1) = 10807
IDAT length with method 37 (fm 2 zl 2 zs 1) = 9593
IDAT length with method 38 (fm 3 zl 2 zs 1) = 12561
IDAT length with method 39 (fm 4 zl 2 zs 1) = 9390
IDAT length with method 40 (fm 5 zl 2 zs 1) = 9579
IDAT length with method 41 (fm 0 zl 3 zs 0) = 9254
IDAT length with method 42 (fm 1 zl 3 zs 0) = 10592
IDAT length with method 43 (fm 2 zl 3 zs 0) = 9354
IDAT length with method 44 (fm 3 zl 3 zs 0) = 12044
IDAT length with method 45 (fm 4 zl 3 zs 0) = 9098
IDAT length with method 46 (fm 5 zl 3 zs 0) = 9343
IDAT length with method 47 (fm 0 zl 3 zs 1) = 9254
IDAT length with method 48 (fm 1 zl 3 zs 1) = 10592
IDAT length with method 49 (fm 2 zl 3 zs 1) = 9354
IDAT length with method 50 (fm 3 zl 3 zs 1) = 12044
IDAT length with method 51 (fm 4 zl 3 zs 1) = 9098
IDAT length with method 52 (fm 5 zl 3 zs 1) = 9343
IDAT length with method 53 (fm 0 zl 4 zs 0) = 6491
IDAT length with method 54 (fm 1 zl 4 zs 0) = 7646
IDAT length with method 55 (fm 2 zl 4 zs 0) = 5354
IDAT length with method 56 (fm 3 zl 4 zs 0) = 8894
IDAT length with method 57 (fm 4 zl 4 zs 0) = 5317
IDAT length with method 58 (fm 5 zl 4 zs 0) = 5442
IDAT length with method 59 (fm 0 zl 4 zs 1) = 6516
IDAT length with method 60 (fm 1 zl 4 zs 1) = 7667
IDAT length with method 61 (fm 2 zl 4 zs 1) = 5344
IDAT length with method 62 (fm 3 zl 4 zs 1) = 8781
IDAT length with method 63 (fm 4 zl 4 zs 1) = 5306
IDAT length with method 64 (fm 5 zl 4 zs 1) = 5425
IDAT length with method 65 (fm 0 zl 5 zs 0) = 6280
IDAT length with method 66 (fm 1 zl 5 zs 0) = 7544
IDAT length with method 67 (fm 2 zl 5 zs 0) = 5280
IDAT length with method 68 (fm 3 zl 5 zs 0) = 8806
IDAT length with method 69 (fm 4 zl 5 zs 0) = 5260
IDAT length with method 70 (fm 5 zl 5 zs 0) = 5354
IDAT length with method 71 (fm 0 zl 5 zs 1) = 6335
IDAT length with method 72 (fm 1 zl 5 zs 1) = 7570
IDAT length with method 73 (fm 2 zl 5 zs 1) = 5290
Could not open output file /cygdrive/c/Users/Oak/Downloads/badappletrace_crush/b
adappletrace0799.png

[Glenn Randers-Pehrson]

Oddly enough, I ran the same command three times, and each time, the error
occurs after a different "IDAT length with method" iteration, in a
seemingly random way.

Very odd. Are you running out of disk space or something, to make
the "open" fail after it has succeeded a few times?

[Glenn Randers-Pehrson]

Please try with the "-v" (verbose) option. The output will be voluminous so please upload it as an attachment rather than embedding it in the comment.