bashrc w/awk print alias problem escaping quotes - bash

Below, the command works great as I'd like. However, inside .bashrc it does not run due to termination of strings. Any advice is happy :)
ps aux | awk '{print $4 "%\t" int($6/1024) " MB\t" $11}' | sort -n
I am simply trying to add something like: alias memusage='command' or function memusage { command }

To keep both memusage alias and original commands, you can put this in .bashrc :
alias memusage="$(cat << 'EOF'
ps aux | awk '{print $4 "%\t" int($6/1024) " MB\t" $11}' | sort -n
EOF
)"

Here's how to define it as a function:
memusage() {
ps aux | awk '{print $4 "%\t" int($6/1024) " MB\t" $11}' | sort -n
}
If you define it on one line, you need a semicolon before the close brace:
memusage() { ps aux | awk '{print $4 "%\t" int($6/1024) " MB\t" $11}' | sort -n; }
Note that the function keyword is a nonstandard bashism; the standard function definition just has () after the name.

For alias, replace the inner 's with '"'"'s:
$ alias memusage='ps aux | awk '"'"'{print $4 "%\t" int($6/1024) " MB\t" $11}'"'"' | sort -n'
Testing it:
$ memusage | grep MEM
%MEM% 0 MB COMMAND

Related

How to grep first match and second match(ignore first match) with awk or sed or grep?

> root# ps -ef | grep [j]ava | awk '{print $2,$9}'
> 45134 -Dapex=APEC
> 45135 -Dapex=JAAA
> 45136 -Dapex=APEC
I need to put the first APEC of first as First PID, third line of APEC and Second PID and last one as Third PID.
I've tried awk but no expected result.
> First_PID =ps -ef | grep [j]ava | awk '{print $2,$9}'|awk '{if ($0 == "[^0-9]" || $1 == "APEC:") {print $0; exit;}}'
Expected result should look like this.
> First_PID=45134
> Second_PID=45136
> Third_PID=45135
With your shown samples and attempts please try following awk code. Written and tested in GNU awk.
ps -ef | grep [j]ava |
awk '
{
val=$2 OFS $9
match(val,/([0-9]+) -Dapex=APEC ([0-9]+) -Dapex=JAAA\s([0-9]+)/,arr)
print "First_PID="arr[1],"Second_PID=",arr[3],"Third_PID=",arr[2]
}
'
How about this:
$ input=("1 APEC" "2 JAAA" "3 APEC")
$ printf '%s\n' "${input[#]}" | grep APEC | sed -n '2p'
3 APEC
Explanation:
input=(...) - input data in an array, for testing
printf '%s\n' "${input[#]}" - print input array, one element per line
grep APEC - keep lines containing APEC only
sed -n - run sed without automatic print
sed -n '2p' - print only the second line
If you just want the APECs first...
ps -ef |
awk '/java[ ].* -Dapex=APEC/{print $2" "$9; next; }
/java[ ]/{non[NR]=$2" "$9}
END{ for (rec in non) print non[rec] }'
If possible, use an array instead of those ordinally named vars.
mapfile -t pids < <( ps -ef | awk '/java[ ].* -Dapex=APEC/{print $2; next; }
/java[ ]/{non[NR]=$2} END{ for (rec in non) print non[rec] }' )
After read from everyone idea,I end up with the very simple solution.
FIRST_PID=$(ps -ef | grep APEC | grep -v grep | awk '{print $2}'| sed -n '1p')
SECOND_PID=$(ps -ef | grep APEC | grep -v grep | awk '{print $2}'| sed -n '2p')
JAWS_PID=$(ps -ef | grep JAAA | grep -v grep | awk '{print $2}')

`df' unexpected' checking for diskspace inside a function using a while loop bash script

I am getting an issue where if I call this function below, I get the error line 89: syntax error at line 117: 'df' unexpected.
If I take the code out of the function it works fine.
Is there any reason for the error above?
This is a bash script on RHEL.
function testr{
df -H | grep -vE '^Filesystem|tmpfs|cdrom' | awk '{ print $5 " " $1 }' | while read output;
do
usep=$(echo $output | awk '{ print $1}' | cut -d'%' -f1)
partition=$(echo $output | awk '{ print $2 }')
(.. Sends alert via mail after)
done
}
Maybe a little easier to read this way?
testr_zsh () {
# This (only) works with zsh.
for usep partition in $( df -H | awk 'NR>1 && !/tmpfs|cdrom/{print $5,$1}' | sed -n '/%/s/%//p' )
do
echo "\$usep: $usep, \$partition: $partition"
done
}
testr () {
for fs in $( df -H | awk 'NR>1 && !/tmpfs|cdrom/{print $5"|"$1}' | sed -n '/%/s/%//p' )
do
usep="$(echo "${fs}" | sed 's/|.*//' )"
partition="$(echo "${fs}" | sed 's/.*|//' )"
echo "\$usep: $usep, \$partition: $partition"
done
}
On my computer not all lines that pass through the awk filter have % in them hence adding the sed filter. zsh allows two vars in the for loop which is pretty slick.

Adding value to global variable in a subshell is not working

I am trying to get the total disk usage of my machine. Below is the script code:
#!/bin/sh
totalUsage=0
diskUse(){
df -H | grep -vE '^Filesystem|cdrom' | awk '{ print $5 " " $1 }' | while read output;
do
diskUsage=$(echo $output | awk '{ print $1}' | cut -d'%' -f1 )
totalUsage=$((totalUsage+diskUsage))
done
}
diskUse
echo $totalUsage
While totalUsage is a global variable, I have tried to sum the individual disk usage to totalUsage in the line:
totalUsage=$((totalUsage+diskUsage))
An echo of totalUsage between do and done shows the correct value,
but when I try to echo it after my call diskUse, it stills prints a 0
Can you please help me, what is wrong here?
The variable totalUsage in a sub-shell doesn't change the value in the parent shell.
Since you tagged bash, you can use here string to modify your loop:
#!/bin/bash
totalUsage=0
diskUse(){
while read output;
do
diskUsage=$(echo $output | awk '{ print $1}' | cut -d'%' -f1 )
totalUsage=$((totalUsage+diskUsage))
done <<<"$(df -H | grep -vE '^Filesystem|cdrom' | awk '{ print $5 " " $1 }')"
}
diskUse
echo $totalUsage
I suggest to insert
shopt -s lastpipe
as new line after
#!/bin/bash
From man bash:
lastpipe: If set, and job control is not active, the shell runs the last command of a pipeline not executed in the background in the current shell environment.

How to reference multiple string values in array in Shell script

I am trying to store multiple string in for loop but it giving me unwanted answer.
My code is :
#!/bin/bash
declare -a arr=("ps -ef | grep icsmpgum | grep $USER | grep -v grep | awk '{print $9,$8}' | awk '{print $1}'")
for i in "${arr[#]}"
do
echo "$i"
done
The output of
ps -ef | grep icsmpgum | grep $USER | grep -v grep | awk '{print $9,$8}' | awk '{print $1}'
is :
icsmpgum
ABC
DEF
I want to refer to these 3 string values in for loop but after applying for loop as mention above it giving me output as :
Output :
ps -ef | grep icsmpgum | grep tsaprm1 | grep -v grep | awk '{print ,}' | awk '{print }'
How should I store these string values in variables ?
You need to use a command substitution, rather than quoting the command:
arr=( $(ps -ef | grep icsmpgum | grep $USER | grep -v grep | awk '{print $9,$8}' | awk '{print $1}') )
I suspect that this will work but there's a lot of further tidying up to be done; all the filtering that you want to do is possible in one call to awk:
arr=( $(ps -ef | awk -v user="$USER" '!/awk/ && /icsmpgum/ && $0 ~ user { print $9 }') )
As mentioned in the comments, there are potential risks to building an array like this (e.g. glob characters such as * would be expanded and you would end up with extra values in the array). A safer option would be to use a process substitution:
read -ra arr < <(ps -ef | awk -v user="$USER" '!/awk/ && /icsmpgum/ && $0 ~ user { print $9 }')

How to escape grep and awk within pipe in an alias?

I want to create an alias for an long command. But I'm not able to escape it correct, I guess it's a problem with the pipes.
My original command
ps aux | grep gimp | awk '{ print $2 '\011' $11 }' | grep -v 'grep'
My attempt for an alias
alias psa="ps aux | grep $1 | awk '{ print \$2 \"\011\" \$11 }' | grep -v 'grep'"
But I get an error that grep can not open file foo (when I do psa foo)
When I remove the last part | grep -v 'grep' then awkthrows the same error.
I prefer an alias before an shell script.
You need to use a function if you want to to insert arguments:
psa() {
ps aux | grep "$1" | awk '{print $2 "\t" $11 }' | grep -v grep
}
You can avoid all the escaping by using a function for this:
myps() {
ps aux | grep gimp | awk '{ print $2 "\011" $11 }' | grep -v 'grep'
}

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