---
name: "pcsc-spy"
section: "1"
platform: "linux"
package: "pcsclite"
version: "2.5.3-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/pcsc-spy"
---

# pcsc-spy(1)

A PC/SC spy command

## NAME

pcsc-spy - A PC/SC spy command

## SYNOPSIS

pcsc-spy \[**-n**\|**--nocolor**\] \[**-d**\|**--diffable**\] \[**-h**\|**--help**\] \[**-v**\|**--version**\] \[**-t**\|**--thread**\] \[*fifo\_filename*\]

## DESCRIPTION

pcsc-spy displays PC/SC calls of an application. It must be used with the *libpcscspy.so.0* library.

To be able to spy the PC/SC layer, the application flow must be modified using `"LIBPCSCLITE_DELEGATE"` so that all PC/SC calls are redirected.

## OPTIONS

- **-d**, **--diffable**

  Remove the variable parts (like handler values) from the output so that two execution can be more easily compared.

- **-h**, **--help**

  Display a short help text.

- **-n**, **--nocolor**

  Disable the output colorization (if you want redirect the output in a file for example).

- **-v**, **--version**

  Print the version of the *pcsc-spy* program plus a copyright, a list of authors.

- **-t**, **--thread**

  Add a thread number before each line of log to identify the calls from the same threads.

## EXAMPLES

We will use the `"LIBPCSCLITE_DELEGATE"` environment variable to load our spying library.

Example:

```
 sh /usr/share/doc/libpcsclite-dev/setup_spy.sh
 export LIBPCSCLITE_DELEGATE=/lib/x86_64-linux-gnu/libpcscspy.so.0
 LIBPCSCLITE_DELEGATE=/lib/x86_64-linux-gnu/libpcscspy.so.0 my_application
```

### Starting the spy tool

```
 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.

## FILES

*~/pcsc-spy* FIFO file is used by *libpcscspy.so.0* to send the raw log lines

## SEE ALSO

[**pcscd**(8)](/pcscd/8.md)

## AUTHOR

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