Command List
| General Commands | |
| Command | Description |
|---|---|
| apropos word | Show commands pertinent to word. |
| which command | Show full path name of command |
| time command | See how long a command takes |
| time cat | Start stopwatch. Ctrl-D to stop. |
| nice info | Run a low priority command (info in this case) |
| renice 19 -p $$ | Make shell (script) low priority. Use for non interactive tasks |
| look prefix | Quickly search (sorted) dictionary |
| grep –color expr…ion /usr/share/dict/words | Highlight occurances of regular expression in dictionary |
| gpg -c file | Encrypt file |
| gpg file.gpg | Decrypt file |
| echo “mail -s ‘get the train’ P@draigBrady.com < /dev/null” | at 17:45 | Email reminder |
| watch -n1 ‘cat /proc/interrupts’ | Watch changeable data continuously |
| alias hd=’od -Ax -tx1z -v’ | Handy hexdump. (usage e.g.: • hd /proc/self/cmdline | less) |
| alias realpath=’readlink -f’ | Canonicalize path. (usage e.g.: • realpath ~/../$USER) |
| set | grep $USER | Search current environment |
| ls /usr/bin | pr -T9 -W$COLUMNS | Print in 9 columns to width of terminal |
| touch -c -t 0304050607 file | Set file timestamp (YYMMDDhhmm) |
| Directory Navigation | |
| Command | Description |
| cd - | Go to previous directory |
| cd | Go to home directory |
| (cd dir && command) | Go to dir, execute command and return to current dir |
| pushd . | Put current dir on stack so you can popd back to it |
| CDROM Commands | |
| Command | Description |
| gzip < /dev/cdrom > cdrom.iso.gz | Save copy of data cdrom |
| mkisofs -V NAME -r dir | gzip > cdrom.iso.gz | Create cdrom image from contents of dir |
| mount -o loop cdrom.iso /mnt/dir | Mount the cdrom image at /mnt/dir (read only) |
| cdrecord -v dev=/dev/cdrom blank=fast | Clear a CDRW |
| gzip -dc cdrom.iso.gz | cdrecord -v dev=/dev/cdrom - | Burn cdrom image (use dev=ATAPI -scanbus to confirm dev) |
| cdparanoia -B | Rip audio tracks from CD to wav files in current dir |
| cdrecord -v dev=/dev/cdrom -audio *.wav | Make audio CD from all wavs in current dir (see also cdrdao) |
| oggenc –tracknum=’track’ track.cdda.wav -o ‘track.ogg’ | Make ogg file from wav file |
| Archives | |
| Command | Description |
| tar -c dir/ | bzip2 > dir.tar.bz2 | Make archive of dir/ |
| bzip2 -dc dir.tar.bz2 | tar x | Extract archive (use gzip instead of bzip2 for tar.gz files) |
| tar c dir/ | gzip | gpg -c | ssh user@remote ‘dd of=dir.tar.gz.gpg’ | Make encrypted archive of dir/ on remote machine |
| find dir/ -name ‘*.txt’ | tar c –files-from=- | bzip2 > dir_txt.tar.bz2 | Make archive of subset of dir/ and below |
| find dir/ -name ‘*.txt’ | xargs cp -a –target-directory=dir_txt/ –parents | Make copy of subset of dir/ and below |
| ( tar c /dir/to/copy ) | ( cd /where/to/ && tar x -p ) | Copy (with permissions) copy/ dir to /where/to/ dir |
| ( cd /dir/to/copy && tar c . ) | ( cd /where/to/ && tar x -p ) | Copy (with permissions) contents of copy/ dir to /where/to/ |
| ( tar c /dir/to/copy ) | ssh -C user@remote ‘cd /where/to/ && tar x -p’ | Copy (with permissions) copy/ dir to remote:/where/to/ dir |
| dd bs=1M if=/dev/hda | gzip | ssh user@remote ‘dd of=hda.gz’ | Backup harddisk to remote machine |
| Rsync | |
| Command | Description |
| rsync -P rsync://rsync.server.com/path/to/file file | Only get diffs. Do multiple times for troublesome downloads |
| rsync –bwlimit=1000 fromfile tofile | Locally copy with rate limit. It’s like nice for I/O |
| rsync -az -e ssh –delete ~/public_html/ remote.com:’~/public_html’ | Mirror web site (using compression and encryption) |
| rsync -auz -e ssh remote:/dir/ <b>.</b> && rsync -auz -e ssh <b>.</b> remote:/dir/ | Synchronize current directory with remote one |
| File Searching | |
| Command | Description |
| alias l=’ls -l –color=auto’ | quick dir listing |
| ls -lrt | List files by date. See also <a href=”scripts/newest”>newest</a> |
| find -name ‘*.[ch]‘ | xargs grep -E ‘expr’ | Search ‘expr’ in this dir and below. |
| find -type f -print0 | xargs -r0 grep -F ’string’ | Search all regular files for ’string’ in this dir and below |
| find -maxdepth 1 -type f | xargs grep -F ’string’ | Search all regular files for ’string’ in this dir |
| find -maxdepth 1 -type f | xargs grep -F ’string’ | Process each item with multiple commands (in while loop) |
| find -type f ! -perm -444 | Find files not readable by all (useful for web site) |
| find -type d ! -perm -111 | Find dirs not accessible by all (useful for web site) |
| locate -r ‘file[^/]*\.txt’ | Search cached index for names. This re is like glob *file*.txt |
| Network | |
| Command | Description |
| ip link show | List interfaces |
| ethtool interface | List interface status |
| ip link set dev eth0 name wan | Rename eth0 to wan |
| ip addr add 1.2.3.4/24 brd + dev eth0 | Add ip and mask(255.255.255.0) |
| ip link set dev interface up | Bring interface up (or down) |
| ip route add default via 1.2.3.254 | Set default gateway to 1.2.3.254 |
| host pixelbeat.org | Lookup ip address for name or vice versa |
| hostname -i | Lookup local ip address (equivalent to host `hostname`) |
| netstat -tupl | List internet services on a system |
| netstat -tup | List active connections to/from system |
| Wget (download tool) | |
| Command | Description |
| (cd cmdline && wget -nd -pHEKk http://www.pixelbeat.org/cmdline.html) | Store local browsable version of a page to the current dir |
| wget -c http://www.example.com/large.file | Continue downloading a partially downloaded file |
| wget -r -nd -np -l1 -A “*.jpg” http://www.example.com/ | Download a set of files to the current directory |
| wget ftp://remote/file[1-9].iso/ | FTP supports globbing directly |
| wget -q -O- http://www.pixelbeat.org/timeline.html | grep ‘a href’ | head | Process output directly |
| echo ‘wget url’ | at 01:00 | Download url at 1AM to current dir |
| wget –limit-rate=20k url | Do a low priority download (limit to 20KB/s in this case) |
| wget -nv –spider –force-html -i bookmarks.html | Check links in a file |
| wget –mirror http://www.example.com/ | Efficiently update a local copy of a site (handy from cron) |
| Windows (samba) | |
| Command | Description |
| smbtree | Find windows machines. See also findsmb |
| nmblookup -A 1.2.3.4 | Find the windows (netbios) name associated with ip address |
| smbclient -L windows_box | List shares on windows machine or samba server |
| mount -t smbfs -o fmask=666,guest //windows_box/share /mnt/share | Mount a windows share |
| echo ‘message’ | smbclient -M windows_box | Send popup to windows machine (off by default in XP sp2) |
| Math | |
| Command | Description |
| echo ‘(1 + sqrt(5))/2′ | bc -l | Quick math |
| echo ‘obase=16; ibase=10; 123′ | bc | Base conversion (decimal to hexadecimal) |
| echo $((0×2dec)) | Base conversion (hex to dec) ((shell arithmetic expansion)) |
| echo ‘pad=20; min=64; (100*10^6)/((pad+min)*8)’ | bc | More complex (int) e.g. This shows max FastE packet rate |
| echo ‘pad=20; min=64; print (100E6)/((pad+min)*8)’ | python | Python handles scientific notation |
| echo ‘pad=20; plot [64:1518] (100*10**6)/((pad+x)*8)’ | gnuplot -persist | Plot FastE packet rate vs packet size |
| String foo | |
| Command | Description |
| sed ’s/string1/string2/g’ | Replace string1 with string2 |
| sed ’s/\(.*\)1/\12/g’ | Modify anystring1 to anystring2 |
| sed ‘/ *#/d; /^ *$/d’ | Remove comments and blank lines |
| sed ‘:a; /\\$/N; s/\\\n//; ta’ | Concatenate lines with trailing \ |
| sed ’s/[ \t]*$//’ | Remove trailing spaces from lines |
| sed ’s/\([\\`\\"$\\\\]\)/\\\1/g’ | Escape shell metacharacters active within double quotes |
| sed -n ‘1000p;1000q’ | Print 1000th line |
| sed -n ‘10,20p;20q’ | Print lines 10 to 20 |
| sort file1 file1 file2 | uniq -u | Show lines in file2 not in file1 |
| echo ‘Test’ | tr ‘[:lower:]‘ ‘[:upper:]‘ | Case conversion |
| tr -dc ‘[:print:]‘ < /dev/urandom | Filter non printable characters |
| grep ‘processor’ /proc/cpuinfo | wc -l | Count lines |
| Calendar | |
| Command | Description |
| cal -3 | Display a calendar |
| cal 9 1752 | Display a calendar for a particular month year |
| date -d fri | What date is it this friday. |
| date –date=’25 Dec’ +%A | What day does xmas fall on, this year |
| date –date ‘1970-01-01 UTC 1234567890 seconds’ | Convert number of seconds since the epoch to a date |
| TZ=’:America/Los_Angeles’ date | What time is it on West coast of US (use tzselect to find TZ) |
| Locales | |
| Command | Description |
| printf “%’d\n” 1234 | Print number with thousands grouping appropriate to locale |
| echo “I live in `locale territory`” | Extract info from locale database |
| locale | cut -d= -f1 | xargs locale -kc | less | List fields in locale database |
| LANG=en_IE.utf8 locale int_prefix | Lookup locale info for specific country. See also <a href=”scripts/ccodes”>ccodes</a> |
| Disk Space | |
| Command | Description |
| ls -lSr | Show files, biggest last |
| du -s * | sort -k1,1rn | head | Show top disk users in current dir. |
| df -h | Show free disk space |
| df -i | Show free inodes |
| fdisk -l | Show disks partitions sizes and types (run as root) |
| rpm -q -a –queryformat ‘%10{SIZE}\t%{NAME}\n’ | sort -k1,1n | List all packages by installed size (Bytes) on rpm distros |
| dpkg-query -W –showformat=’${Installed-Size;10}\t${Package}\n’ | sort -k1,1n | List all packages by installed size (KBytes) on deb distros |
| dd bs=1 seek=2TB if=/dev/null of=ext3.test | Create a large test file (taking no space) |
| Monitoring / Debugging | |
| Command | Description |
| strace -c ls >/dev/null | Summarise/profile system calls made by command |
| strace -f -e open ls >/dev/null | List system calls made by command |
| ltrace -f -e getenv ls >/dev/null | List library calls made by command |
| lsof -p $$ | List paths that process id has open |
| lsof ~ | |
| tcpdump not port 22 | Show network traffic except ssh. |
| ps -e -o pid,args –forest | List processes in a hierarchy |
| ps -e -o pcpu,cpu,nice,state,cputime,args –sort pcpu | sed ‘/^ 0.0 /d’ | List processes by % cpu usage |
| ps -e -o rss=,args= | sort -b -k1,1n | pr -TW$COLUMNS | List processes by mem usage. |
| ps -C firefox-bin -L -o pid,tid,pcpu,state | List all threads for a particular process |
| ps -p 1,2 | List info for particular process IDs |
| for wtmp in `ls -t /var/log/wtmp*`; do last reboot -f $wtmp; done | grep reboot | Show system reboot history. |
| free -m | Show amount of (remaining) RAM (-m displays in MB) |
| System Info | |
| Command | Description |
| hdparm -i /dev/hda | Show info about disk hda |
| hdparm -tT /dev/hda | Do a read speed test on disk hda |
| badblocks -s /dev/hda | Test for unreadable blocks on disk hda |
| mount | column -t | Show mounted filesystems on the system (and align output) |
| cat /proc/partitions | Show all partitions registered on the system |
| grep MemTotal /proc/meminfo | Show RAM total seen by the system |
| grep “model name” /proc/cpuinfo | Show CPU(s) info |
| lspci -tv | Show PCI info |
| lsusb -tv | Show USB info |
| Recode (Obsoletes iconv, dos2unix, unix2dos) | |
| Command | Description |
| recode -l | less | Show available conversions (aliases on each line) |
| recode windows-1252.. file_to_change.txt | Windows “ansi” to local charset (auto does CRLF conversion) |
| recode utf-8/CRLF.. file_to_change.txt | Windows utf8 to local charset |
| recode iso-8859-15..utf8 file_to_change.txt | Latin9 (western europe) to utf8 |
| recode ../b64 < file.txt > file.b64 | Base64 encode |
| recode /qp.. < file.txt > file.qp | Quoted printable decode |
| recode ..HTML < file.txt > file.html | Text to HTML |
| recode -lf windows-1252 | grep euro | Lookup table of characters |
| echo -n 0×80 | recode latin-9/x1..dump | Show what a code represents in latin-9 charmap |
| echo -n 0×20AC | recode ucs-2/x2..latin-9/x | Show latin-9 encoding |
| echo -n 0×20AC | recode ucs-2/x2..utf-8/x | Show utf-8 encoding |
| Interactive | |
| Command | Description |
| mc | Powerful filemanager that can browse rpm, tar, ftp, ssh, … |
| screen | Virtual terminals with detach capability, … |
| links | Web browser |
| gnuplot | Interactive/scriptable graphing |
| octave | Matlab like environment |
Useful Commands
Dumping a mySQL to a sql file
mysqldump -l --opt databasename > /root/file/location/filename.sql -u user --password=whateverthepass
Importing mySQL dump file
mysql databasename < /root/file/location/filename.sql -u user --password=whateverthepass
Copying Entire Folder of Files
cp - Ru /root/file/location/* /where/it/should/go --reply=yes
Copying an entire folder to another server
tar zcf - localfolder/ \ | ssh 192.1.1.1 "cd folder/to/copy/to; tar zpxvf -"
If you want to extract one file from the .tar.gz file use
gzip -dc file.tar.gz | tar xf - pathname/filename
The pathname and filename should be exactly as given in the .tar.gz file. If you want more than one file append their names, again include pathname, at the end of the command.
Symlinking (Source –> Location)
ln -s /source/foldername /folder/where/symlink/will/be
Useful Commands would be REALLY useful if I could read them - near zero contrast - black on black.
Nice cheat sheets!
Cheers,
Adrian
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