Useful Unix
nslookup query DNS for host/domain information
<CTRL>-r search backwards through command history (bash)
lynx textual html browser
killall [process name] kill process by name (similiar to kill)
ps -aux process status
grep -Rai [string] search for the existance of [string] in all non-binary files (-a), case insensative (i), recursive through all directories (R)
ps -aux | grep -i [process] pipe process results to grep to find [process]
mpage powerful print to printer command
lpr standard print to printer command
lpq show jobs in the print queue
lpd start the print daemon
ldconfig determines runtime bindings
![command] recalls and runs the latest [command]
tail -f like tail, but keeps updating
ln -s symlink
<CTRL>-c standard interrupt
less [file] then type SHIFT-f waits for data
netstat -rn shows network status
df diskspace
whois domain name directory service
wc -l [file] line count of [file] (word count with -l switch)
mount -tmsdos /dev/fd0 floppy read a dos formatted floppy
tar -zxvf [file] extrct a tape archive file
w see who's logged in and what they are doing
route [add|delete] manually manipulate routing tables
<CTRL>-w, <CTRL-u> on some terminals erase a partially entered password
press any key upon startup, type boot -s, type mount -a single user mode
find -mtime 24 finds all files modified within 24 days
ls -la `locate filename` printout info on located files
host [] look up host names using DNS
<CTRL-a> go to the beginning of a command line
<CTRL-u>, <CTRL-e> go to the end of a command line
chpass change user information
/etc/services check for port assignments
sort sort lines of text files
uniq report or filter out repeated lines in a file
gunzip file.tgz; tar -xf file.tar unarchive compressed and archived files
strings [file] prints the printable strings in a file
ipcs check shared memory and semaphores
ircrm remove a shared memory
-- when placed in a command line statement, says 'no more switches after here'
'./-c' specifies the file named -c in a command line statement
du -sk * displays how much memory is taken up by everything in *
tar -cpf - directory | ssh -l login "(cd /path/to/remote_directory && tar -xpf -)" Moves a directory from one machine to another
gzip < /path/to/log > log.gz; echo -n > /path/to/log A good way to archive log files
split -l line-number-to-split-on file prefix Splits a file on each number
iostat -c 20 display kernal I/O stats on terminal, device and cpu operations (count 20)
/var/spool/mqueue Where to check for spooled emails
crontab -l, crontab -e list, edit crontab entries; but shouldn't be done this way