Unix Commands

find

// find all files by name in current and sub-directories
find -name "file.name"

// find all files by name case insensitive in current and sub-directories
find -iname "file.name"

// find all files by name not matching in current and sub-directories
find -not -name "file.name"

// find files by size
find ~ -size (+100M more than|-100M less than|100M exacty)

general

// show current directory
pwd

// got to last directory
cd -

// shutdown now
shutdown -h now

// shutdown in 10 minutes
shutdown -h +10

// reboot the system
shutdown -r now

// display disk size for director
du -hs [directory-path]

// display the disk space usage
df -h

// display the type of file system
df -T

// search current process for app
ps -ef | grep app_name

// stop a process
kill -9 ####

// remove file with confirmation
rm -f filename

// remove files and directories recusively
rm -r filename

// copy file preserving mode, ownership and timestamp
cp -p filename1 filename2

// copy file with confirmation before overwritting
cp -i filename1 filename2

// move file with confirmation
mv -i filename1 filename2

// verbose mode for move
mv -v filename1 filename2

// show contents of files
cat filename1 filename2 -n (shows line numbers)

// change file permissions
chmod permissions filename

// change ownership
chown -R (recursively) user filename

// change your password
passwd -d (disables password) (USERNAME)

// show network information
ifconfig -a

// display information about the system
uname -a

// find where a command is
whereis ls

// find out what a command is
whatis ls

// print the last lines of a file
tail -n # (last # of lines) -f (view in real-time) fiename

// set the system date
date -s "01/31/2010 23:59:53"

// sync hardware clock with system date
hwclock –systohc
hwclock --systohc –utc

// download file
wget -O filename (store in different filename) -c (continue incomplete download) -b (download in background) url

// download urls from file
wget -i download-urls.txt

// download all pdf's from website
wget -r -A.pdf http://url-to-webpage-with-pdfs/

grep

// search file for string
grep "search string" filename


// search files for a string
grep "search string" filename.pattern

// search directory for string
grep -r "search string" .

// case insensitive file search
grep -i "search string" filename

// regex file search
grep "regex pattern" filename

// search file for full words, not sub-strings
grep -iw "search" filename

// display lines that do no match the search string
grep -v "search string" filename

// get a count of the matches
grep -c "search string" filename

// get only the filenames of the files that match
grep -l "search string" filename_*

// show the line numbers for the string matches
grep -n "search string" filename

ls

// show all information about files/directories
ls -l

// show file size in human readable format
ls -lh

// sort results based on modified time
ls -lt

// sort results based on reversed modified time
ls -ltr

// list one file per line
ls -1

// show information about current directory
ls -ld

// show hidden files
ls -a

// show all files recursively
ls -R

tar

// create new tar (uncompressed)
tar cvf archive_name.tar dirname/

// extract from tar
tar xvf archive_name.tar

// view tar
tar tvf archive_name.tar

// create new gzip tar (compressed)
tar cvzf archive_name.tar.gz dirname/

// extract a gzip tar
tar xvfz archive_name.tar.gz

// view gzip tar
tar tvfz archive_name.tar.gz

// add a file or directory to an existing tar
tar rvf archive_name.tar newdir/

// add a file or directory to an existing gzip tar
tar rvfz archive_name.tar.gz newdir/