exiftool performance benchmark

[Phil Harvey]

From a program, just open todo.arg in append mode.

- Phil

[jean]

It's a good idea, thank you Phil 

[jean]

Is it possible to dialog with Exiftool.exe using pipes ?
I create a process with exiftool, then i create two pipes for reading from and writing to exiftool.
The read pipe uses stdoutput.
I can read the errors with the pipe but not the infos (Exif and so on).
Where are those infos returned by exiftool supposed to go 

[Phil Harvey]

If you use "-@ -", you should be able to handle all I/O with 3 pipes:

1) exiftool receives command-line arguments from STDIN

2) exiftool writes tag information to STDOUT

3) exiftool writes error messages to STDERR

- Phil

[jean]

are you sure that stdin can be redirected ?

[Phil Harvey]

Excerpt from a Bourne shell session to prove this works:

Code Select Expand

> ls -l a.jpg b.jpg
ls: b.jpg: No such file or directory
-rwxr-xr-x   1 phil  phil  281767 Nov 17 12:09 a.jpg

> cat a.arg
a.jpg
b.jpg
-filename

> cat a.arg | exiftool -@ - 1>std.out 2>err.out

> cat std.out
======== a.jpg
File Name                       : a.jpg
    1 image files read
    1 files could not be read

> cat err.out
File not found: b.jpg


- Phil

Edit: To make things easier to see, I could have redirected stdin directly from a file rather than piping the output of "cat".  The effect of this command is the same:

Code Select Expand

exiftool -@ - <a.arg 1>std.out 2>err.out

[jean]

I meant redirecting stdin under Windows, creating a process for exiftools.exe and giving it pipes for stdin, stdout and stderr.
I can get stdout if i create the process giving parameters such as "-EXIF:All test.jpg"
In that case i don't use stdin.

but if i just create the process with "-@ -" i can(t give parameters using the pipe redirecting stdin

[Phil Harvey]

I'm not a Windows programmer, and I don't even know what programming language you are using, but redirecting stdin is very common, and it should be possible from any platform/language.

- Phil

[jean]

Yes, i use redirecting since years with many programs, but i can''t make that work with Exiftools.
(I use C)

[Phil Harvey]

Sorry for the delay, but I had to wait until I got home to try this in windows:

exiftool -@ - <a.arg 1>std.out 2>err.out

This exact command works perfectly in the Windows cmd shell.  Undoubtedly this shell is written in C (or C++), so there must be some way for you to do this from C in Windows.

I'm thinking that maybe you are having problems because you aren't flushing the file piped to exiftool's stdin after writing?  Any write buffering by your program could put a wrench in the whole works (as noted in my -stay_open documentation).

- Phil

[jean]

I'm going to investigate a little more, i will post my results 

A small bug: -lang does not seem to work:

exiftools.exe -lang it -EXIF:All test.jpg

returns:

Invalid or unsupported language 'it'
then the list of Available languages (with it)

[Phil Harvey]

Invalid or unsupported language 'it'
then the list of Available languages (with it)

It sounds like your exiftool installation is bad.  My guess is that lib/Image/ExifTool/Lang/it.pm is missing or corrupted.  Try re-installing.

- Phil

[jean]

I recompile it, using pp.
I added it.pm in the file pp_build_exe.argc
When exiftool is launched it creates its temp folder, and in this temp folder it.pm is copied twice, one under
inc\lib\image\exiftool\lang and one under inc\lib

[jean]

I tried a lot of different manners, none works 
can you explain how you add a single line in the pp_build_exe.ergs ?

[Phil Harvey]

Attached is my current copy of pp_build_exe.args

- Phil