| #!/bin/bash |
| if[ $# -lt 1 ] ; then |
| echo “Usage: “ |
| echo ” threads_per_process.sh PID | process name [count] “ |
| echo “” |
| echo “Example” |
| echo ” PID: 36434 or” |
| echo ” process string: NumThreads (this script will do a ps -ef|grep NumThreads to get the PID)” |
| echo ” The last number is the number of times the command will run” |
| echo “” |
| echo ” threads_per_process.sh 36434 20″ |
| echo ” threads_per_process.sh 36434 “ |
| echo ” threads_per_process.sh NumThreads” |
| echo ” threads_per_process.sh NumThreads 20″ |
| echo “” |
| exit 1 |
| fi |
| echo “========================================================” |
| echo “The number of threads is displayed under the column NLWP” |
| echo “========================================================” |
| PROCESS_ID=$1 |
| COLUMNS=140 |
| DELAY=3 |
| if[ $# -gt 1 ] ; then |
| DELAY=$2 |
| shift |
| fi |
| DEFAULT_COUNT=1 |
| COUNT=1 |
| if[ $# -gt 1 ] ; then |
| COUNT=$2 |
| DEFAULT_COUNT=0 |
| fi |
| PATTERN=`echo $1 | sed ‘s/[0-9]//g’` |
| if[!–z $PATTERN ];then |
| # string |
| PROCESS_ID=`ps -ef |egrep -v ‘grep|threads_per’ |grep $1|awk ‘{print $2}’` |
| echo “The PID to lookup is: “$PROCESS_ID |
| fi |
| CMD=“COLUMNS=$COLUMNS ps -p $PROCESS_ID -o pid,%cpu,rss,etime,nlwp,args” |
| CMD2=“COLUMNS=$COLUMNS ps -p $PROCESS_ID h -o pid,%cpu,rss,etime,nlwp,args” |
| PATTERN=`echo $PROCESS_ID | sed ‘s/\ /@/g’ | sed ‘s/[0-9]//g’` |
| n=0 |
| HEADER_COUNT=15 |
| if[–z $PATTERN ];then |
| if[ $COUNT –ge 1];then |
| while[ $n –lt $COUNT ];do |
| PROCESS_ID=`ps -e |awk ‘{print $1}’ | grep $PROCESS_ID` |
| if[–z $PROCESS_ID ];then |
| echo “The monitored PID no longer exists. Exiting.” |
| exit 0; |
| fi |
| if[ $HEADER_COUNT ==0];then |
| HEADER_COUNT=15 |
| fi |
| if[ $HEADER_COUNT ==15];then |
| eval $CMD|awk ‘{now=strftime(“%Y-%m-%d %T “); print now $0}’ |
| else |
| eval $CMD2|awk ‘{now=strftime(“%Y-%m-%d %T “); print now $0}’ |
| fi |
| HEADER_COUNT=$(expr $HEADER_COUNT –1) |
| if[ $DEFAULT_COUNT –eq 1];then |
| n=0 |
| else |
| n=$(expr $n +1) |
| fi |
| if[ $n –lt $COUNT ];then |
| sleep $DELAY |
| fi |
| done |
| fi |
| else |
| echo “The keyword \”$1\” return more than one PID. Please consider constraining the keyword” |
| fi |
|
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Linux common SHELL 6. sed -i ‘/ Root / s / no / yes /’ / etc / ssh / sshd_config sed in this text in Root row, matching Root line, replace the no into a yes. The display runs three levels of open services: 13. The number of CPU’s (multi-accounting multiple CPU, cat / proc / cpuinfo | grep -c processor), the more low system load, the number of requests per second can handle the more. 28 Process # top -id 1 1 build file links shell programming, to achieve the following functions: awk ‘/ as / && / end / {print $ 1};! / bd / && / end / {print $ 1};!’ in / A / {} line containing the A’s 3. 2 extracted from the file path for the file name and path name of the command basename, dirname 3 command substitution, the results of the implementation of a command assigned to a variable, use `, or $ () Requirements: Completion of this program in a script user.list follows #back message #user add #back message #add users to groups for ((q = 1; q <= 3; q ++)) usermod -G ‘awk “NR == $ q {print $ 2}” user.list | awk’ {print $ 2} “‘awk” NR == $ q {print $ 1} ” if (($? == 0))
No. mission command combination Basics Scripts Perl is a script language, which is compiled each time before running. That unix knows that it is a perl script there must be the following header at the topline of every perl script: #!/usr/bin/perl where the path to perl has to be correct and the line must not exeed 32 charachters. After the header line: #!/usr/bin/perl there are either empty lines with no effect or commandlines or commentary lines. Everything from and behind a “#” up to the end of the line is comment and has no effect on the program. Commands start with the first non space charachter on a line and end with a “;”. So one can continue a command over several lines and terminates it only with the semicolon. Normal commands are executed in the order written in the script. But soubroutines can be placed anywhere and will only be evaluated when called from a normal commandline. Perl knows it’s a soubroutine if it the code is preceeded with a “sub” and enclosed in a block like: sub name { command;} Perl can include other programming code with: require something or with use something. Single quote: ” or: q// That perl distinguishes between scalar and list context is the big feature, which makes it uniqe and more usful then most other script languages. A soubroutine can return lists and not only scalars like in C. Or an array gives the number of elements in a scalar context and the elements itself in a list context. The enormous value of that feature should be evident. Variables and Operators General There are scalar variables, one and two dimensional arrays and associative arrays. Instead of declaring a variable one preceeds it with a spcial charachter. $variable is a normal scalar variable. @variable is an array and %variable is an associative array. The user of perl does not have to distinguish between a number and a string in a variable. Perl switches the type if neccessary. Fill in a scalar with: $price = 300; $name = “JOHN”; Calculate with it like: $price *= 2; $price = $oldprice * 4; $count++; $worth–; Print out the value of a scalar with: print $price,”\n”; Fill in a value: $arr[0] = “Fred”; $arr[1] = “John”; Print out this array: print join(‘ ‘,@arr),”\n”; Fill in a single element with: $hash{‘fred’} = “USA”; $hash{‘john’} = “CANADA”; Fill in the entire hash: Put something into a variable with a “=” or with some combined operator which assignes and and does something at the same time: $var = “string”; Puts the string into $var $var .= “string”; Appends string to $var Modify and assigne with: ($new = $old) =~ s/pattern/replacement/; Compare strings with: eq ne like in: $name eq “mary”. And/Or/Not Acct on success or failure of an expression: $yes or die; means exit if $yes is not set. AND,OR and NOT are regularly used in if() statements: . Branching if if(condition){ command if condition; unless(condition){ command unless condition; while while(condition){ # Go prematurely to the next iteration # Prematureley abort the loop with last # Prematureley continue the loop but do continue{} in any case # Redo the loop without evaluating while(condtion) command while condition; until(condition){ until(condition){ until(condition){ until(condition){ command until condtion; # Iterate over @data and have each value in $_ # Get each value into $info iteratively # Iterate over a range of numbers # Eternal loop with (;;) # syntax File test operators check for the status of a file: Some examples: Regular Expressions What it is A regular expression is an abstract formulation of a string. Usually one has a search pattern and a match which is the found string. There is also a replacement for the match, if a substitution is made. A pattern stands for either one, any number, several, a particular number or none cases of a character or a charachter-set given literaly, abstractly or octaly. One can replace found matches with a replacement with the s/pattern/replacement/; statement. To change the content of a variable do: $var =~ s/pattern/replacement/; Output a value from a variable print $var,”\n”; printf(“%-20s%10d”,$user,$wage); chomp() (perl5) removes a newline if one is there. The chop() (perl4) removes any last character. chomp($var = ); open(IN,”<filename”) || die “Cannot open filename for input\n”; open(AAA,”<infile”) || die “Cannot open infile\n”; open(OUT,”>file”) || die “Cannot oben file for output\n”; open(IN,”<file”) || die “Cannot open file\n”; The empty filehandle “<>” reads in each file iteratively. The name of the current processed file is in $ARGV. For example print each line of several files prepended with it’s filename: Get current directory at once @dir = <*>; while(<*>){ @files = ; This is the official way of globbing: Readdir() Perl can also read a directory itself, without a globbing shell. This is faster and more controllable, but one has to use opendir() and closedir(). Process Data from a Unix Pipe open(IN,”unixcommand|”) || die “Could not execute unixcommand\n”; open(OUT,”|more”) || die “Could not open the pipe to more\n”; Execute a Unix Command and forget about the Output system(“someprog -auexe -fv $filename”); If it’s just one line or a string: chomp($date = qx!/usr/bin/date!); The chomp() (perl5) removes the trailing “\n”. $date gets the date. If it gives a series of lines one put’s the output into an array: chomp(@alllines = qx!/usr/bin/who!); exec anotherprog; But then the perl program is gone. The Perl builtin Functions String Functions Get all upper case with: $name = uc($name); Get expressions for which a command returned true: @found = grep(/[Jj]ohn/,@users); Open a file for input: open(IN,”/path/file”) || die “Cannot open file\n”; Number to character: chr $num; Define a Subroutine sub mysub { &mysub; &mysub(@data); As global variables: Some of the Special Variables SYNTAX MEANING $_ String from current loop. e.g. for(@arr){ $field = $_ . ” ok”; } Forking Forking is very easy! Just fork. One puts the fork in a three way if(){} to separately the parent, the child and the error. Building Pipes for forked Children Building a Pipe pipe(READHANDLE,WRITEHANDLE); select(WRITEHANDLE); $| = 1; select(STDOUT); pipe(FROMCHILD,TOCHILD); select(TOCHILD); $| = 1; select(STDOUT); if($pid = fork){ # Somwhere at the beginning of the script # Prepare infos # Socket # Flush socket # Connect # Print to socket # Read from socket # Or read a single character only # Close the socket Get the password entry for a particular user with: @entry = getpwnam(“$user”); One can informations for group, host, network, services, protocols in the above way with the commands: getgrnam, getgrid, gethostbyname, gethostbyaddr, getnetbyname, getnetbyaddr, getservbyname, getservbyport, getprotobyname, getprotobynumber. If one wants to get all the entries of a particular categorie one can loop through them by: setpwent; For example: Get a list of all users with their homedirectories: Arithmetics Addition: + Formatting Output with “format” This should be simplification of the printf formatting. One formats once only and then it will be used for every write to a specified filehandle. Prepare a format somwhere in the program: format filehandle = Now use write to print into that filhandle according to the format: write FILEHANDLE; The @<<< does left adjustment, the @>>> right adjustment, @##.## is for numericals and @||| centers. Command line Switches Show the version number of perl: perl -v; Principle of Script Defining the Shell Type To make a ksh script (which is a ksh program) crate a new file with a starting line like: Four Types of Lines A script has four types of lines: The shell defining line at the top, empty lines, commentary lines starting with a # and command lines. See the following top of a script as an example for these types of lines: #!/usr/bin/ksh # Commentary…… file=/path/file The script starts at the first line and ends either when it encounters an “exit” or the last line. All “#” lines are ignored. Start and End of Command A command starts with the first word on a line or if it’s the second command on a line with the first word after a”;’. print -n “Name: “; read name; print “” One can continue commands over more than one line with a “\” immediately followed by a newline sign which is made be the return key: grep filename | sort -u | awk ‘{print $4}’ | \ The script mus not have a name which is identical to a unix command: So the script must NOT be called “test”! Variables Filling in When filling into a variable then one uses just it’s name: state=”US” and no blanks. There is no difference between strings and numbers: price=50. Using When using a variable one needs to put a $ sign in front of it: print $state $price. Arrays Set and use an array like: arrname[1]=4 To fill in There are happily no declarations of variables needed in ksh. One cannot have decimals only integers. Branching if then fi if [[ $value -eq 7 ]];then if [[ $value -eq 7 ]] if [[ $value -eq 7 ]];then print “$value is 7”;fi if [[ $name = “John” ]];then if [[ $name = “John” ]];then case $var in while do done while [[ $count -gt 0 ]];do until [[ $answer = “yes” ]];do for foo in $(ls);do One can skip the rest of a loop and directly go to the next iteration with: “continue”. while read line while read line;do (Officially they are called “positional parameters”) The number of command line arguments is stored in $# so one can check for arg;do Comparisons To compare strings one uses “=” for equal and “!=” for not equal. if [[ $name = “John” ]];then if [[ $price -lt 1000 || $name = “Hanna” ]];then Variable Manipulations Removing something from a variable Variables that contain a path can very easily be stripped of it: ${name##*/} gives you just the filename. If we wanted $foo or if not set 4 then: ${foo:-4} but it still remains unset. To change that we use: This is very important if our program relays on a certain vaiable: ${foo:?”foo not set!”} ${foo:+1} gives one if $foo is set, otherwise nothing. Ksh Regular Expressions Ksh has it’s own regular expressions. Especially in ksh there are quantifiers for whole patterns: ?(pattern) matches zero or one times the pattern. So one can question a string in a variable like: if [[ $var = fo@(?4*67).c ]];then … Functions Description A function (= procedure) must be defined before it is called, because ksh is interpreted at run time. One can make one in either of the following two ways: foo(){ To call it just put it’s name in the script: foo. To give it arguments do: foo arg1 arg2 … The return statement exits the function imediately with the specified return value as an exit status. Data Redirection General Data redirection is done with the follwoing signs: “> >> < <<". Every program has at least a standardinput, standardoutput and standarderroroutput. All of these can be redirected. Command Output to File For writing into a new file or for overwriting a file do: command > file For appending to a file do: command >> file Standard Error Redirection To redirect the error output of a command do: command 2> file To discard the error alltogether do: command 2>/dev/null To put the error to the same location as the normal output do: command 2>&1 File into Command If a program needs a file for input over standard input do: command < file
Combine Input and Output Redirection
command < infile > outfile Commands into Program ( Here Document ) Every unix command can take it’s commands from a text like listing with: command < An awk script can have three types of blocks. One of them must be there. The BEGIN{} block is processed before the file is checked. The {} block runs for every line of input and the END{} block is processed after the final line of the input file. awk ‘ Awk autosplits a line on whitespace as default. The fields are stored in $1 through $NF and the whole line is in $0. One can match or not match an individual field. awk ‘ Awk can do for() loops like in c++ and has the normal if and while structures. In NR is current line number and in NF the number of fields on the current line. awk ‘ Extract email addresses from incoming mail. The mail would be guided to the following script from within the ~/.forward file. This is not an eficient method, but only an example to show serial processing of text. The next example will do the same thing within awk only and will be efficient. The mail comes in over standardinput into the script. if [[ $(grep -c $addr /path/antimailfile) -gt 0 ]];then mail $addr < With #!/usr/bin/nawk -f the whole script is interpreted intirely as an awk script and no more shell escapes are needed, but one can and has to do everything in awk itself. It’s nawk because of the getline function. This script es an example only. For really extracting email addresses several special cases would have to be considered… #!/usr/bin/nawk -f # Lines from a mail are dropping in over stdin. Append every line to a { print >> “/path/mymailfile” } # Find lines with with From: or Replay: at beginning. /^From:/ || /^Replay/ { # Find fields with @. Iterate over the fields and check for @ for(i=1;i<=nf;i++){ if($i ~ /@/){ # Clean the email addresses with gsub() gsub(/[<>()”]/,””,$i) # Check whether the email address is in the antimailfile while( getline antiaddr < "/path/antimailfile" ){
# Compare actual address in $i with loaded address
if($i == antiaddr){
# Send a negative mail
system("mail " $i " < /path/badmail")
# Now end the while loop
break
}else{
# Send a positive mail
system("mail " $i " < /path/goodmail")
}
}
}
}
}
Calculate on columns and print formated output
If one has a formated input of number columns one can still split them on white space, but has to consider the format for output with printf()
#!/usr/bin/nawk -f
# Reprintet lines without foo or boo
! /(foo|boo)/ { print }
# Rearange and calculate with columns but only on lines with foo or boo
/(foo|boo)/ {
# Extract fields
mytype = $1
var1 = $2
var2 = $3
var3 = $4
# Calculate
if(mytype == "foo"){
var1 *= 10
var2 += 20
var3 = log(var3)
}
if(mytype == "boo"){
var1 *= 4
var2 += 10
var3 = cos(var3)
}
# Print formated output in reverse order
printf("%-4s%10.3f%10.3f%10.3f\n",mytype,var3,var2,var1)
}
How to iterate over each word of a shell variable in awk
In this example there is first a shell variable filled in and then it is given to awk. Awk splits it into an array and then iterates over the array and looks for each word on the current line of a file. If it finds it, it prints the whole line.
#!/usr/bin/ksh
var="term1 term2 term3 term4 term5"
awk '
BEGIN { split(myvar,myarr) }
{
for(val in myarr){
if($0 ~ myarr[val]){
print
}
}
}
' myvar="$var" file
Functions
This example substitutes the first three occurences of "searchterm" with a different term in each case and from the fourth case it just prints the line as it is.
It should show where to place a function and how to call it.
#!/usr/bin/nawk -f
BEGIN{
mysub1 = "first_sub"
mysub2 = "second_sub"
mysub3 = "third_sub"
mycount = 1
find = "searchterm"
}
{
if($0 ~ find){
if(mycount == 1){ replace(mysub1); }
if(mycount == 2){ replace(mysub2); }
if(mycount == 3){ replace(mysub3); }
if(mycount > 3){ print; } sub(find,mysub) As an example for a CGI script in awk I make one which presents the unix man pages in html. man.cgi String functions sub(regexp,sub) Substitute sub for regexp in $0 Perl can do 100 times more than awk can, but awk is present on any standard unix system, where perl first has to be installed. And for short commands awk seems to be more practical. The autosplit mode of perl splits into pieces called: $F[0] through $F[$#F] which is not so nice as $1 through $NF where awk retains the whole line in $0 at the same time. awk ‘{print $1}’ infile Biggest 10 Files List All the Process By memory usage find how many files an application is using Highest CPU Usage Total Memory Usage CPU Threshold Current User With Session Count Memory Details Swap memory Details Process Using memory Largest File Or Directory Processes Count Used By Users Who Started this Process How Much Ram Is Being Used When Was the Process Started Environment Variables belong to a Process List Threads by Pid along with Thread Start Time CPU usage for EACH cores Memory Percentage Usage of a Process Total CPU Usage Percentage Find Class Files inSide the Jar Location Find the Class File in jars Search The File From Multiple Jar Files List of Files That Are Open For Writing to Disk See which Process is Holding the File List the files accessed by a program get size of data that haven’t been written to disk yet Owner of the File determine which application is utilizing a certain port? Number of sessions waiting for ACK (SYN Flood) java 1142 dwls977 925u IPv6 141713891 0t0 TCP localMachine :27710->eth0.remoteMachine.nova.com:54141 (ESTABLISHED) Incoming Connections remoteMachine:root002-~ $ netstat | grep 54426 Zero Length File Sizes Find The MAC Address List all the Installed Perl packages The Output would be some thing like this SSh and Execute a Command Count Threads OF a Process Print a stack trace of a running process Drop all the Connections available now for a Port Find and Grep a File Find the Time took Process To Complete Memory Information ( Much Better than Free Command) All process Running as a Specific User Find and Zip files matching a Pattern How to list all unique ip address currently connected to a specific port Find and Gzip Find and Remove Find Files That are Updated in The Last 60 Minutes Find all files Older than 2 days and gzip them How many Open Tomcat Threads Differences between 2 files in remote hosts [root@vx111a perl]# df -T file1 lsof -i tcp:10012 How To Find The Number Of Open Files for a Process Name and process pid sorted by number of open files.? Show connections based on the host and the port using @host:port Grep All Files Of A Certain File Type For A Specific Pattern Top 20 Process With High File Descriptors Ping a URL to Find the HTTP Status Dev:Hunter@root-~ $ nc -zw2 vx111a 10011 || echo http service is down Dev:Hunter@root-~ $ curl -sL -w “%{http_code}\\n” “http://vx111a:10011/wls_monitor/” -o /dev/null Redirect and Print The 2>/dev/null at the end of the find command tells your shell to redirect the error messages (FD #2) to /dev/null, so you don’t have to see them on screen. Use /dev/null to to send any unwanted output from program/command. All data written on a /dev/null special file is discarded by the system. To redirect standard error to /dev/null and store file list to output.txt, type: Find Who is Using Port Dev:vx111a:djbs002-~ $ lsof -i tcp:10012 Search For Out Of memory Conenct to the Linux Machine From windows Machine to Download Files Note : pscp is available with putty Software which is free to download Obtain the Number of Thread States in a Thread Dump #!/bin/bash TOP 12 ‘PS’ PERFORMANCE COMMANDS admin@UM 02:03 AIX, Unix # ps aux|head -1; ps aux|sort -rn +2|head -10 # ps aux|head -1; ps aux|sort -rn +3|head # ps -eakl|head -1; ps -eakl|sort -rn +5 # ps -eakl|sort -n +6|head # ps -eakl|sort -n +7 # ps vx|head -1;ps vx|grep -v PID|sort -rn +3|head -10 # ps vx|head -1; ps vx|grep -v PID|sort -rn +6|head -10 # ps vx|head -1; ps vx|grep -v PID|sort -rn +4|head -10 # ps -a -o pid, user, class, pcpu, pmem, args # ps vg|head -1; ps vg|grep -w wait # ps -mo THREAD -p # topas -P Find Memory Usage System memory used and free Total Used and Free Memory in MBytes (in that order) free -m|grep “buffers/cache”|cut -d”:” -f2 Raw ps -e -orss=,args= | sort -b -k1,1n | pr -TW$COLUMNS ps -e -orss=,args= | sort -b -k1,1n | awk ‘{ split( “KB MB GB” , v ); s=1; while( $1>1024 ){ $1/=1024; s++ } print int($1) ” ” v[s] ” ” $2 }’ Raw ps -e -orss=,args= | awk ‘{arr[$2]+=$1} END {for (i in arr) {print arr[i],i}}’ | sort -b -k1,1n ps -e -orss=,args= | awk ‘{arr[$2]+=$1} END {for (i in arr) {print arr[i],i}}’ | sort -b -k1,1n | awk ‘{ split( “KB MB GB” , v ); s=1; while( $1>1024 ){ $1/=1024; s++ } print int($1) ” ” v[s] ” ” $2 }’ ps -e -orss= | awk ‘{ sum += $1 } END { print sum }’ ps -e -orss= | awk ‘{ sum += $1 } END { print sum }’ | awk ‘{ split( “KB MB GB” , v ); s=1; while( $1>1024 ){ $1/=1024; s++ } print int($1) ” ” v[s] ” ” $2 }’ smem -w -t -k Dear Reader, In a production environment Java Profiling is not an option, we have seen multiple times that Fortunately, Java comes with some great debugging tools, co-operating those tools with Linux I am going to explain below items here: 1) Introduction: Any java program starts when the JVM calls the main method, this creates a thread The idea here: 2) Step-by-step process: Below are the sample output when you execute the command: Explanation: “jps” – Java Virtual Machine Process Status Tool, a command in Unix. “106” shows 106 The next step is to get the CPU usage per each LWP related to the main process, we can use below commands: The newly created file threadsList.txt will contain below things in similar way (The headers will not be To see headers too, just execute the below command: Explanation: PID is process Id. Now take the thread dump and kill the process Id: 8243. Open the thread dump file and search value “2035”. //Killing process 3) “jmap” – Memory Map (dump): Prints shared object memory maps or heap memory details of a given JVM process. 4) “jmap” – Histo: See below command: num #instances #bytes class name 5) List of open files in Linux: dmodiUnixUser@productName79:~$ lsof | grep PROCESS_ID > help.txt |
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