List POSIX signal information for all processes.
- Easy to use (just
sigscan) - Blazingly fast (~95% of time spent in kernel space)
- Uses colors if output is detected as a terminal that supports them (or forcibly with
--(no-)colors).
- Only classic POSIX signals are supported, no real-time signals.
- Relies on
/procand therefore only works on Linux.
sigscan is available for downloads as pre-compiled binaries or you can build it from source.
You can find binaries on the releases page or tweak + run the code below in your shell to install it to your system.
# Pick a download target
ARCH="x86_64" # or aarch64, riscv64gc
LIBC=gnu # or musl
INSTALL_DIR="/usr/local/bin/"
LATEST_VERSION=$(curl -s https://raw.githubusercontent.com/brannondorsey/sigscan/refs/heads/main/Cargo.toml | grep -Po '^version = "\K[^"]*')
# Download and install it
curl -L "https://github.com/brannondorsey/sigscan/releases/download/v${LATEST_VERSION}/sigscan-${ARCH}-unknown-linux-${LIBC}.tar.gz" \
| tar xz sigscan \
&& sudo mv sigscan "${INSTALL_DIR}"
# Verify installation
sigscan# Install rustup, if you don't already have it
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
# Install sigscan
cargo install --path signal-scan
# Verify installation
sigscan# Show all processes with caught, blocked, and pending signals (default)
sigscan
# Show only processes that are ignoring signals (omitted by default)
sigscan --ignored
# Show caught, blocked, pending, **and** ignored signals (equivalent to `sigscan -cbpi`)
sigscan --caught --blocked --pending --ignored
# Or use --all/-a instead of specifying all four signal types, plus processes with empty signal masks
sigscan --all
# Show only processes with totally empty signal masks (e.g. no signals are caught, blocked, pending, or ignored)
sigscan --emptysigscan subscribes to the Unix philosophy of doing one thing and doing it well. It can be combined with other tools to answer more complex questions.
# Paginate output
sigscan --color | less
# Show all signal info pertaining to a certain process
sigscan -cpbi --color | grep firefox
# Get PIDs of processes that are blocking any type of signal
sigscan --blocked | cut -d" " -f1
# Find potential daemon processes (catching SIGHUP)
sigscan --caught | grep HUP | cut -d" " -f2
# Get the full command line of processes that are catching TERM
sigscan --caught | grep TERM | cut -d" " -f1 | xargs ps -o pid,cmd
# Find processes that might be zombies (blocking SIGCHLD)
sigscan --blocked | grep CHLD | awk '{print $1}' | xargs ps -o pid,ppid,state,cmd
# Continuously watch for processes with pending signals
watch --color -n 0.1 "sigscan --pending --color"$ sigscan --help
List POSIX signal information for all processes.
By default -c (--caught), -b (--blocked), and -p (--pending) are set.
However, any of these options you specify will override and reset the defaults.
Example: sigscan -cbp
Note: This tool only supports classic POSIX signals, not real-time signals
(e.g. SIGRTMIN and above).
Usage: sigscan [OPTIONS]
Options:
-i, --ignored
Show processes that are ignoring signals
-c, --caught
Show processes that are catching signals
-b, --blocked
Show processes that are blocking signals
-p, --pending
Show processes that have pending signals
--cmdline
Replace the binary name with the full value of /proc/$PID/cmdline surrounded by quotes
--color
Force enable colored output (can also be set via FORCE_COLOR env var)
--no-color
Force disable colored output (can also be set via NO_COLOR env var)
--examples
Print the examples section from the README
-h, --help
Print help (see a summary with '-h')
-V, --version
Print versionsigscan is dual-licensed under either of:
at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you shall be dual licensed as above, without any additional terms or conditions.