Trying to print awk variable - awk

I am not much of an awk user, but after some Googling, determined it would work best for what I am trying to do...only problem is, I can't get it to work. I'm trying to print out the contents of sudoers while inserting the server name ($i) and a comma before the sudoers entry as I'm directing it to a .csv file.
egrep '^[aA-zZ]|^[%]' //$i/etc/sudoers | awk -v var="$i" '{print "$var," $0}' | tee -a $LOG
This is the output that I get:
$var,unixpvfn ALL = (root)NOPASSWD:/usr/bin/passwd
awk: no program given
Thanks in advance

egrep is superfluous here. Just awk:
awk -v var="$i" '/^[[:alpha:]%]/{print var","$0}' //"$i"/etc/sudoers | tee -a "$LOG"
Btw, you may also use sed:
sed "/^[[:alpha:]%]/s/^/${i},/" //"$i"/etc/sudoers | tee -a "$LOG"

You can save the grep and let awk do all the work:
awk -v svr="$i" '/^[aA-zZ%]/{print svr "," $0}' //$i/etc/sudoers
| tee -a $LOG
If you put things between "..", it means literal string, and variable won't be expanded in awk. Also, don't put $ before a variable, it will indicate the column, not the variable you meant.

Related

Is using awk at least 'awk -F' always will be fine?

What is the difference on Ubuntu between awk and awk -F? For example to display the frequency of the cpu core 0 we use the command
cat /proc/cpuinfo | grep -i "^ cpu MHz" | awk -F ":" '{print $ 2}' | head -1
But why it uses awk -F? We could put awk without the -F and it would work of course (already tested).
Because without -F , we couldn't find from wath separator i will begin the calculation and print the right result. It's like a way to specify the kind of separator for this awk's using. Without it, it will choose the trivial separator in the line like if i type on the terminal: ps | grep xeyes | awk '{print $1}' ; in this case it will choose the space ' ' as a separator to print the first value: pid OF the process xeyes. I found it in https://www.shellunix.com/awk.html. Thanks for all.

AWK print between two characters

When I try this command:
/usr/bin/curl -s sketch*.zip "https://www.sketch.com/downloads/mac/" |\
grep 'download.sketchapp.com/sketch-' | awk 'NR==1{print $3}'
The output is:
content="0;URL='https://download.sketchapp.com/sketch-68.2-102594.zip
what I am looking to get is:
68.2
Any help would be appreciated.
It seems you want to extract the number after your pattern, only for the first matcing row. You can use one grep command:
... | grep -oPm1 '(?<=download.sketchapp.com/sketch-)[^-]+' file
or as this is the 3rd field of your 1st curl output row you want, you can use one awk command (split field using hyphen as separator to array and print the element in the middle):
awk '/download.sketchapp.com/sketch-/ && NR==1 {split($3,a,"-"); print a[2]; exit}'
Using sed:
/usr/bin/curl -s sketch*.zip "https://www.sketch.com/downloads/mac/" | \
sed -n 's!.*download.sketchapp.com/sketch-\([^-]*\).*!\1!p;' | \
head -1
head is to get rid of multiple matches. sed command extracts non-hyphen characters after download.sketchapp.com/sketch-.

using awk command to get the correct name

I want to get the filename from a long string in shell script.After reading some example from likegeeks.com,I write a simple solution:
#/bin/bash
cdnurl="http://download.example.com.cn/download/product/vpn/rules/vpn_patch_20190218162130_sign.pkg?wsSecret=9cadeddedfr7bb85a20a064510cd3f353&wsABSTime=5c6ea1e7"
echo ${cndurl}
url=`echo ${cdnurl} | awk -F'/' '{ print $NF }'`
result=`echo ${url} | awk -F '?' '{ print $1}'`
echo ${url}
echo ${result}
I just want to get vpn_patch_20190218162130_sign.pkg,and the it does.I wonder is there any smart ways (may be one line).
If behind pkg it's not ?,how to use pkg to get the filename,I am not sure if always ? after pkg,but the filename always be *.pkg.
You can try : this is more robust as compare to second awk command:
echo "$cdnurl"|awk -v FS='/' '{gsub(/?.*/,"",$NF);print $NF}'
vpn_patch_20190218162130_sign.pkg
#less robust
echo "$cdnurl"|awk -vFS=[?/] '{print $(NF-1)}'
You should use sed :
sed -r 's|.*/(.*.pkg).*|\1|g'

Dereferencing variables in awk

Why doesn't this work?
x=5
$ ls -l | awk '{print $(($x))}'
should print field 5 of ls -l command, right?
The only ways you should pass in the value of shell variable to awk are the following
$ x=5
$ ls -l | awk -v x="$x" '{print $x}'
$ ls -l | awk '{print $x}' x="$x"
The main difference between these two methods is that by using -v the value of x is set in the BEGIN block whilst the second method the value would not be set. All other methods with quoting tricks or escaping should not be used unless you like headaches.
However you don't want to being parsing ls at all, the command you really want is:
stat --printf="%s\n" *
Assuming the fifth column of your ls is the same as mine, this will display all the file sizes in the current directory.
You could access the shell variable something similar to these;
The first way is not suggested!
x=5
ls -l | awk '{print $'$x'}'
or assigning the value x to the variable shellVar, before execution of the program begins
x=5
ls -l | awk -v shellVar="$x" '{print $shellVar}'
or using an array containing the values of the current environment
export x=5
ls -l | awk '{print $ENVIRON["x"]}'
That's a shell variable, which is not expanded by the shell in single quotes. The reason we put awk scripts in single quotes is precisely to prevent the shell from interpreting things meant for awk's benefit and screwing things up, but sometimes you want the shell to interpret part of it.
For something like this, I prefer to pass the value in as an awk variable:
ls -l | awk -v "x=$x" '{print $x}'
but you could do any number of other ways. For instance, this:
ls -l | awk '{print $'$x'}'
which should really be this:
ls -l | awk '{print $'"$x"'}'
alternatively, this:
ls -l | awk "{print \$$x}"
Try this :
ls -l | awk '{print $'$x'}'

awk capability cut capability

I am using the following ssh command to get a list of ids. Now I want to
get only ids greater than a given number in the list of ids; let's say "231219" in this case. How can I incorporate that?
I have a local file "ids_ignore.txt"; anyid we put in this list should be ignored by the command..
Can awk or cut do the above?
ssh -p 29418 company.com gerrit query --commit-message --files --current-patch-set \
status:open project:platform/code branch:master |
grep refs | cut -f4 -d'/'
OUTPUT:-
231222
231221
231220
231219
230084
229092
228673
228635
227877
227759
226138
226118
225817
225815
225246
223554
223527
223452
223447
226137
... | awk '$1 > max' max=8888 | grep -v -F -f ids_ignore.txt
Or, if you want to do it all with awk:
... | awk 'NR==FNR{ no[$1]++ }
NR!=FNR && $1 > max && ! no[$1]' max=NNN ids_ignore.txt -
cut cannot do numeric comparison on the input fields, it's just a simple field extraction tool. awk can do the work of grep and cut:
ssh -p 29418 company.com gerrit ... |
awk -F/ -v min=231219 '
NR == FNR {ignore[$1]; next}
/refs/ && $4>min && !($4 in ignore) {print $4}
' ids_ignore.txt -
The trailing - is important at the end of the awk command: it tells awk to read from stdin after it reads the ids_ignore file.