Disk, filesystem
Disk usage
{linux}$ du -sh
{freebsd}$ du -sh
Count subdirectories in current directory:
{linux}$ du –max-depth=1
{freebsd}$ du -d1
Typical approach to find biggest directories/files on disk:
{linux}$ du –max-depth=1 -kx|sort -n
{freebsd}$ du -d1 -kx|sort -n
Find some kinds of files (regex is a mask for full path, no need for begin/end marks)
{linux}$ find . -regextype posix-extended -type f -regex “.*\.(java|class)”
{freebsd}$ find -E . -type f -regex “.*\.(java|class)”
Show open files and programs:
{linux}$ lsof
{freebsd}$ fstat
Some networking
Show open ports and apps connected to them:
{linux}$ netstat -apne –inet
{freebsd}$ sockstat
Kernel issues
Show loaded modules:
{linux}$ lsmod
{freebsd}$ kldstat
Load kernel module:
{linux}$ modprobe SomeModule
{freebsd}$ kldload SomeModule
Remove loaded module:
{linux}$ rmmod SomeModule
{freebsd}$ kldunload SomeModule
Program development
Trace the system calls of a program:
{linux}$ strace
{freebsd}$ truss  (strace is also available in /usr/ports/deve/strace)
libraries – show all paths + libs:
{linux}$ ldconfig -p
{freebsd}$ ldconfig -r
Packages management
Different linux distros make it own way. I’ll focus on debian-based distributions like Debian, Ubuntu, Kubuntu etc. Find which package this file belongs to?
{freebsd}$ pkg_info -W /path/to/file
{linux}$
Have we got a package like… (in (k)ubuntu you can use more friendly tools like synaptic, apt-get)
{linux}$ apt-cache search your_name
{freebsd}$ cd /usr/ports; make search key=your_name
just in package names:
{freebsd}$ locate -i your_name | grep “/usr/ports/”
Install a binary package
{linux}$ apt-get install package_name
{freebsd}$ pkg_add -r package_name
Install a package from sources
{linux}$ is there a simple way to do it?
{freebsd}$ cd /usr/ports/path/package; make install clean
