經常使用Linux命令

This is a linux command line reference for common operations.

Examples marked with ? are valid/safe to paste without modification into a terminal, so you may want to keep a terminal window open while reading this so you can cut & paste.
All these commands have been tested both on Fedora and Ubuntu.

個人實踐環境：redhat-release-5Server-5.4。

apropos whatis	Show commands pertinent to string. See alsothreadsafe
man -t man | ps2pdf -> man.pdf	make a pdf of a manual page
which command	Show full path name of command
time command	See how long a command takes
time cat	Start stopwatch. Ctrl-d to stop. See also sw
nice info	Run a low priority command (The 「info」 reader in this case)
renice 19 -p $$	Make shell (script) low priority. Use for non interactive tasks

man -t man | ps2pdf -> man.pdf 默認用不了。 到http://www.ghostscript.com/download/gsdnld.html下載ghostscript，當前最新版本時9.0.4。

配置的時候，告知須要更高版本的glibc。

升級一下glibc吧，到ftp://ftp.gnu.org/gnu/glibc/下載。配置的時候又報：

configure: error: gcc must provide the <cpuid.h> header

 
一查，原來又要升級GCC，https://bugs.gentoo.org/292174?id=292174。

耐着性子去http://gcc.gnu.org/，又Download最新的GCC4.6.1，配置時又報一堆依賴的東東。

想一想何須呢，爲了這麼個ghostscript費這麼大週摺，找個低版本的試試吧。因而下載了ghostscript-9.02，配置，編譯，安裝，一切都很順利。

再來運行 man -t man | ps2pdf -&gt; man.pdf，這回就OK了。

看看pdf效果。

which command 也是極其有用的一個命令。 

公司的雲平臺不少東西都是預先設好的，起初我連java安裝在哪裏都不知道，找了半天。有了找個命令，一下搞定。

目錄導航 dir navigation

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

 

文件查找 file searching

alias l='ls -l -color=auto'	quick dir listing
ls -lrt	List files by date. See also newest andfind_mm_yyyy
ls /usr/bin | pr -T9 -W$COLUMNS	Print in 9 columns to width of terminal
find -name '*.[ch]' | xargs grep -E 'expr'	Search ‘expr’ in this dir and below. See alsofindrepo
find -type f -print0 | xargs -r0 grep -F 'example'	Search all regular files for ‘example’ in this dir and below
find -maxdepth 1 -type f | xargs grep -F 'example'	Search all regular files for ‘example’ in this dir
find -maxdepth 1 -type d | while read dir; do echo $dir; echo cmd2; done	Process each item with multiple commands (in while loop)
find -type f ! -perm -444	Find files not readable by all (useful for website)
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
look reference	Quickly search (sorted) dictionary for prefix
grep -color reference /usr/share/dict/words	Highlight occurances of regular expression in dictionary

alias l='ls -l -color=auto' 在RHEL下應爲 alias l='ls -l --color=auto'。原文中有不少這樣的錯誤，兩個「-」，變成了一個長的「—」估計做者也是在Windows下寫的。

歸檔壓縮 archives and compression

gpg -c file	Encrypt file
gpg file.gpg	Decrypt file
tar -c dir/ | bzip2 > dir.tar.bz2	Make compressed 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/sda | gzip | ssh user@remote 'dd of=sda.gz'	Backup harddisk to remote machine

試試加密解密，就加密剛剛建立的man.pdf吧。

 

重複輸入passphrase。

完後查看，會在當前目錄生成一個.gpg文件。

再來試着解密，輸入剛纔的passphrase。

tar -c dir/ | gzip | gpg -c | ssh user@remote 'dd of=dir.tar.gz.gpg' 感受不是很實用，加密時會讓你輸入passphrase，ssh登陸也須要輸入用戶密碼，重疊到一塊兒，容易弄錯。

rsync (Network efficient file copier: Use the –dry-run option for testing)

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/ . && rsync -auz -e ssh .remote:/dir/	Synchronize current directory with remote one

上面的命令默認連遠程用戶的root 用戶，換成同事的帳號試了試。

rsync -P user@remote:/home/user/sync/hadoop-0.21.0.tar.gz test-hadoop.tar.gz

rsync --bwlimit=1000 hadoop-0.21.0.tar.gz local-hadoop-0.21.0.tar.gz

設成1000，速度還真是慢，現學現用了一把 time。

time rsync --bwlimit=1000000000 hadoop-0.21.0.tar.gz local-hadoop-0.21.0.tar.gz

rsync -az -e ssh --delete hadoop-0.21.0.tar.gz user@remote:'/home/user/sync/hadoop-0.21.0.tar.gz'

沒大弄明白這條命令到底作什麼用。

第四條命令，搞不懂後面的 && rsync -auz -e ssh .remote:/dir/ 是幹嗎的，下面這條就能夠同步遠程目錄到當前目錄。

rsync -auz -e ssh user@remote:/home/user/sync/ .

ssh (Secure SHell)

ssh $USER@$HOST command	Run command on $HOST as $USER (default command=shell)
ssh -f -Y $USER@$HOSTNAME xeyes	Run GUI command on $HOSTNAME as $USER
scp -p -r $USER@$HOST: file dir/	Copy with permissions to $USER’s home directory on $HOST
ssh -g -L 8080:localhost:80 root@$HOST	Forward connections to $HOSTNAME:8080 out to $HOST:80
ssh -R 1434:imap:143 root@$HOST	Forward connections from $HOST:1434 in to imap:143

ssh 屬於常見命令，再也不囉嗦，提一下xeyes，能夠參見 http://en.wikipedia.org/wiki/Xeyes。

wget (multi purpose download tool)

(cd dir/ && wget -nd -pHEKkhttp://www.joinebook.com/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.joinebook.com/linux-command.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)

第一條命令的連接已經失效，另外-pHEKk後還須要一個空格和URL分開。

wget -nd -pHEKk http://www.joinebook.com/linux-command.html

中斷下載測試，下載QQ Linux 版玩玩吧，wget http://3.duote.org/qq2011beta3.zip

中斷再繼續，wget -c http://3.duote.org/qq2011beta3.zip

echo 'wget http://www.joinebook.com/linux-command.html' | at 01:00

networking (Note ifconfig, route, mii-tool, nslookup commands are obsolete)

ethtool eth0	Show status of ethernet interface eth0
ethtool --change eth0 autoneg off speed 100 duplex full	Manually set ethernet interface speed
iwconfig eth1	Show status of wireless interface eth1
iwconfig eth1 rate 1Mb/s fixed	Manually set wireless interface speed
iwlist scan	List wireless networks in range
ip link show	List network interfaces
ip link set dev eth0 name wan	Rename interface eth0 to wan
ip link set dev eth0 up	Bring interface eth0 up (or down)
ip addr show	List addresses for interfaces
ip addr add 1.2.3.4/24 brd + dev eth0	Add (or del) ip and mask (255.255.255.0)
ip route show	List routing table
ip route add default via 1.2.3.254	Set default gateway to 1.2.3.254
tc qdisc add dev lo root handle 1:0 netem delay 20msec	Add 20ms latency to loopback device (for testing)
tc qdisc del dev lo root	Remove latency added above
host boykma.pro	Lookup DNS ip address for name or vice versa
hostname -i	Lookup local ip address (equivalent to host `hostname`)
whois joinebook.com	Lookup whois info for hostname or ip address
netstat -tupl	List internet services on a system
netstat -tup	List active connections to/from system

轉到這裏，已然有些倦了，留待下次完成剩餘部分。

原文地址：http://www.joinebook.com/linux-command.html。