Commands
CUT:
lspv | cut -c 6-7 lists the hdisks numbers (cuts the 6th and 7tn character (disk nubers))
dlnkmgr view -drv | grep -w 00000 | awk '{print $4}' | cut -d . -f 3
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EXPR: integer arithmetic
\* multiplication (\ is needed to tell * is not a special character)
/ division
% remainder
+ addition
- substraction
expr \( 6 + 4 \) / 2 5
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FIND: recursively searches the directory tree
find / -xdev -type f -name "cor*" -size +10000c -exec ls -l {} \;
/ where to find
-xdev looks only in the given fs
-type f what type to look for (f: file, d: direcory)
-name "cor*" name to look for
-size +10000c search for the given size (+10000c : greater than 10000 character (larger then 10kbyte))
-size +2 search for greater than 1kbyte (bloxk size is 512 byte, that's why +2 is given)
-exec ls -l {} \; what command to execute
({}: it represents each findings and \; is needed at the end of line)
e.g. find /home -xdev -name "*.old" -exec rm {} \;
-mtime -1 file modifocation date is less then 1 day (+1 means older than 1 day)
find . -name '*.ksh' -ok rm {} \; this will ask if the command (rm) should be executed or not (much safer if find is not perfect)
find /etc/rc.d -ls it lists the files and dirs in the given dir
find /tmp/bb -exec awk '/func/ {print FILENAME}' {} \; it will check in /tmp/bb if any files contains the word "func" and list those
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GREP: (Global Regular Expression Parser) The grep command searches for the pattern.
grep -i ignore case (small letter or capital)
grep -c displays only a count of matching lines
grep -n shows line number at the beginning of the matching line
grep -v invert the sense of matching, to select non-matching lines
grep -w selects only whole words
grep -l lists the name of the files (once) which contain matching line (grep -l paging00 *)
ps -ef | egrep 'ssh|aix' select lines with ssh and aix
errpt -a|grep -A1 'NAME' selects lines with NAME and shows 1 line after that (A: after, B: before)
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HEAD, TAIL:
head filename displays first 10 lines of the file
head -50 filename displays first 50 lines
tail filename displays last 10 lines of the file
tail -50 filename displays last 50 lines
tail +15 filename displays the file starting from the 15th line
tail -f filename used when we are monitoring the file (interactively shows how the file is changing)
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LSOF:
NETWORK
-n no host name resolution
-P not converts port numbers to port names
lsof -i show all network connections
lsof -i| grep LISTEN shows what ports are waiting for connections
lsof -i | grep ESTABLISHED shows current active connections
lsof -i tcp list only TCP connections (works with udp as well)
lsof -i :<port> shows all connections of a given port (lsof -i :22 or lsof -i :ssh)
lsof -i @<host> shows connections to a specific host (lsof -i @192.168.1.5)
lsof -i protocol:@ip:port this is the syntax for network findings (protocol: tcp or udp, @ip: any ip address, port: a port number)
lsof -a -u <user> -i shows all network activity of a user (-a combines -u and -i)
USER, FILES, PROCESSES
lsof -u <user> shows what is open for a user (lsof -u oracle)
lsof <file> shows what is using a file (lsof /var/adm/syslog.log)
lsof <directory> shows what pids are using the filesystem (directory) (it can be good if we cannot umount)
lsof +D <directory> shows which file is open by which process in a directory (lsof +D /usr)
(+D will show recurcively the open files, otherwise only device name would be shown)
lsof -N list all NFS files
lsof -c <command> shows files and network connections a command is using (lsof -c ssh)
lsof -p <pid> shows what a proccess ID has open (lsof -p 335545)
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HOW TO FIND WHAT FILES ARE OPENED BY A PID
1.
root@aix20: /root # lsof -p 319660
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
ovcd 319660 root 32r VREG 10,5 12153 69705 /usr (/dev/hd2)
(it will show the filesystem and the indode number (69705))
2.
root@aix20: /root # find /usr -inum 69705
/usr/lpp/VV/msg/en_US/sec.cm.client.cat
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METACHARACTERS, VARIABLES:
GREP SHELL
single character . ?
multicharacter .* *
character range [x-z] [x-z]
begins a line ^ N/A
ends a line $ N/A
variable N/A $
HOME home directory
$PS1 prompt symbol
set displays the values of all shell variables
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RSYNC:
Much
like cp, rsync copies files from a source to a destination. Unlike cp,
the source and destination of an rsync operation can be local or remote.
rsync can resume a transfer after interruption; it transfers only those
portions of a file that differ between source and destination; and
rsync can perform entire or incremental backups.
By
default, rsync uses Secure Shell (SSH) as its transport mechanism; you
can reuse your machine aliases and public keys with rsync
rsync -av /tmp/bb_rs30 /tmp/bb it will copy the directory (/tmp/bb_rs30) and its contents under /tmp/bb
rsync -av /tmp/bb_rs30/ /tmp/bb it will copy the contents of the named directory but not the directory itself (check / at the end)
-v option enables verbose messages
-a option (stands for archive), is a shorthand for -rlptgoD:
recurse, copy symbolic links as
symbolic links, preserve permissions, preserve file times,
preserve group, preserve owner, and preserve devices and special files, respectively
rsync -n -av /tmp/bb_rs30/ /tmp/bb -n: previews what will happen but does not move a single byte (it is good for testing)
rsync -av /tmp/bb_rs30/ aix2:/tmp/bb_rs20 it will copy the contents of the given dir to the other host
(assuming the same login name on the remote machine)
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SORT:
cat /etc/passwd | sort -t: -n +2
-t: gives the delimeter character (here :, deafult is the space)
-n numerical order
+2 sort by the 3rd column
-r reverse order
df -m | sort -n +3 | egrep '9.%|100%' sorts by the 4th column (%) of the filesstems, which are 90-100% full
cat animals | sort +0.1 sort the file animals by the second character of the first word
ls -lR |sort -nk 5|tail -20 sorts the 20 largest file
lspv | sort -k1.6n list hdisk in numerical order (lspv|sort -tk +1 -n <--it is the same (delimiter is "k")
lspv | sort -k1,1.5 -k1.6n list hdisks then vpaths in numeric order
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TAR:
tar -cvf /tmp/file.tar . saves where we are to the given path (-c: create, -v: verbose, -f: file)
tar -cvf conf.tar conf creates conf.tar of the dir conf
tar -xvf /tmp/file.tar extracts the tar file (-x: extract)
tar -xvf -C /home/bb /tmp/file.tar it will extract the tar file to /home/bb
tar -tvf /tmp/file.tar list (verify) the content of a tar file
tar -cf - * | gzip -9 > vmi.tar.gz makes tar and zip wehere we are
tar cvf - openssh5.8p1 | gzip -c > openssh5.8p1.tgz creates tgz in one command
tar: 0511-197 DirectorServer: Cannot write data extracted with the tar command:
A file cannot be larger than the value set by ulimit.
I changed these ulimit settings after that it was OK (dont't forget to logout and login again)
root@bb_lpar: /bb # chuser fsize=-1 fsize_hard=-1 root
root@bb_lpar: /bb # chuser data=-1 data_hard=-1 root
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TRUSS:
truss <command> it will show what system calls a command makes
truss -c -p <pid> it will trace a process (-c: counts the system calls rather than displaying them, -p: pid)
truss -d -p <pid> -o
truss -t open lsps -a shows whatis needed for the given command (here lsps -a)
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XARGS:
lspv|awk '{print$1}'|xargs it will list the elements in a line separated with space
cat list | xargs -t rm will rm all the files which are in the file list
ls | xargs -t -I {} mv {} {}.old it will rename to .old all the file in the current dir
-t it echoes the constructed command (trace mode) (it is optional)
-I {} insert each line of the ls to that place where the {} symbol appear
lsdev -Cc disk | xargs -n1 rmdev -dl removes all the listed disks
-n1 1 element will be passed each time to xargs (if n2 then the command will be created with 2 elements)
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ZIPPING:
gzip-V shows gzip version
gzip file1 zip
gzip -d file1.gz unzip
gzip -9 filename will zip (and remove the file automatically)
gunzip filename unzipping it
gzip -c file > file.gz it creates a zip file but leave the original file as well
> filename after that original file can be emptied
compress file1 the original file will be deleted and a new compressed file will be created with a .Z at the end
zcat file1.Z displays the compressed files (without uncompression)
uncomress file1.Z uncompressing a file (the compressed one will be deleted)
if you receive this:
gunzip SysDir6_2.tar.gz
gunzip: SysDir6_2.tar: File too large
this is because gzip 1.2.4 (or lower gzip versions) need a patch to accept large files, workaround for this problem:
gzip -d -c SysDir6_2.tar.gz| tar xvf -
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OTHER:
file <filename> shows the type of a file
diff file1 file2 compares only text files
cmp file1 file2 compares all types of files
dircmp dir1 dir2 compares directories
time cp file1 /home show the time to accomplish the command (godd for performance analysis)
ps $$ shows which shell is in use
echo $SHELL shows the current shell
printenv view environmental variables
cat -vet file shows tabs, enters... as viewable characters
-v displays non-printing characters as visible characters
-t displays tab as ^I
-e displays enter as $
!!! sh -xv <command...> for troubleshooting, if a command fails, you can see where exactly it failed in the command script!!!
(sh -xv exportvg rootvg)
dd if=/dev/zero of=/home/user/bb/4GB_file bs=1m count=4000 it creates a 4GB file
lmktemp <filename> <size_in_bytes> it creates a file with given size
alias dir='ls' creates an alias
unalias dir removes an alias
set - unset
df -g | awk '{sum = sum + $3} END {print sum}' it sums up the fs in gigabyte (by the 3rd column)
for i in `ls -l | grep old | awk '{print $9}'` ; do du -sk $i; done | awk '{sum = sum + $1} END {print sum}'
generating random passwords:
dd if=/dev/urandom bs=16 count=1 2>/dev/null | openssl base64 | sed "s/[=O/\]//g" | cut -b1-8