DOKK / manpages / debian 12 / libpcsclite-dev / pcsc-spy.1.en
PCSC-SPY(1) PC/SC lite PCSC-SPY(1)

pcsc-spy - A PC/SC spy command

pcsc-spy [-n|--nocolor] [-d|--diffable] [-h|--help] [-v|--version] [-t|--thread] [fifo_filename]

pcsc-spy displays PC/SC calls of an application. It must be used with the libpcscspy.so library.

To be able to spy the PC/SC layer, the application flow must be modified so that all PC/SC calls are redirected. Two options are available:

dlopen(3)

Remove the variable parts (like handler values) from the output so that two execution can be more easily compared.
Display a short help text.
Disable the output colorization (if you want redirect the output in a file for example).
Print the version of the pcsc-spy program plus a copyright, a list of authors.
Add a thread number before each line of log to identify the calls from the same threads.

We will use the standard "LD_PRELOAD" loader option to load our spying library.

Example:

 LD_PRELOAD=/usr/lib/x86_64-linux-gnu/libpcscspy.so pcsc_scan

This is the case for the PC/SC wrappers like pyscard (for Python) and pcsc-perl (for Perl). The LD_PRELOAD mechanism can't be used. Instead we replace the libpcsclite.so.1 library by the spying one.

You may use install_spy.sh and uninstall_spy.sh to install and uninstall the spying library.

Using the spying library without pcsc-spy is not a problem but has side effects:

- a line "libpcsclite_nospy.so.1: cannot open shared object file: No such file or directory" will be displayed

- some CPU time will be lost because of the PC/SC calls redirection

 pcsc-spy

If a command argument is passed we use it instead of the default ~/pcsc-spy FIFO file. It is then possible to record an execution log and use pcsc-spy multiple times on the same log.

To create the log file just do:

 mkfifo ~/pcsc-spy
 cat ~/pcsc-spy > logfile

and run your PC/SC application.

~/pcsc-spy FIFO file is used by libpcsclite.so.1 to send the raw log lines

pcscd(8)

This manual page was written by Ludovic Rousseau <rousseau@free.fr>

2023-04-11 pcsc-lite 1.9.9