Bash function arguments - bash

My problem is that prepinace_grepu, which is $3 inside of function, evaluates to -i instead of -i -n as I expected it to be .
How can I change it to work? And I cant put it in two variables, because I want it to be flexible and just take it as a string , so it will work even if prepinace_grepu="-c -v -i -f" etc...
compare()
{
semka $2 $1 /etc/passwd /etc/shadow | sort > result1.txt
grep $3 $1 /etc/passwd /etc/shadow | sort > result2.txt
diff result2.txt result1.txt > diff.txt
if [[ -s diff.txt ]] ;
then echo "FAIL"
else echo "OK"
fi ;
}
pattern=Hojny
prepinace_moje="-vi"
prepinace_grepu="-i -n"
compare $pattern $prepinace_moje $prepinace_grepu

Quote the variables in shell as much as you can:
pattern="Hojny"
prepinace_moje="-vi"
prepinace_grepu="-i -n"
compare "$pattern" "$prepinace_moje" "$prepinace_grepu"
Since prepinace_grepu contains space you must send it in quotes otherwise called function will only get -i and $3 and -n as $4.

Related

How to filter an ordered list stored into a string

Is it possible in bash to filter out a part of a string with another given string ?
I have a fixed list of motifs defined in a string. The order IS important and I want to keep only the parts that are passed as a parameter ?
myDefaultList="s,t,a,c,k" #order is important
toRetains="k,t,c,u" #provided by the user, order is not enforced
retained=filter $myDefaultList $toRetains # code to filter
echo $retained # will print t,c,k"
I can write an ugly method that will use IFS, arrays and loops, but I wonder if there's a 'clever' way to do that, using built-in commands ?
here is another approach
tolines() { echo $1 | tr ',' '\n'; }
grep -f <(tolines "$toRetains") <(tolines "$myDefaultList") | paste -sd,
will print
t,c,k
assign to a variable as usual.
Since you mention in your comments that you are open to sed/awk , check also this with GNU awk:
$ echo "$a"
s,t,a,c,k
$ echo "$b"
k,t,c,u
$ awk -v RS=",|\n" 'NR==FNR{a[$1];next}$1 in a{printf("%s%s",$1,RT)}' <(echo "$b") <(echo "$a")
t,c,k
#!/bin/bash
myDefaultList="s,t,a,c,k"
toRetains="s,t,c,u"
IFS=","
for i in $myDefaultList
do
echo $toRetains | grep $i > /dev/null
if [ "$?" -eq "0" ]
then
retained=$retained" "$i
fi
done
echo $retained | sed -e 's/ /,/g' -e 's/,//1'
I have checked it running for me. Kindly check.

bash: sed: unexpected behavior: displays everything

I wrote what I thought was a quick script I could run on a bunch of machines. Instead it print what looks like might be directory contents in a recursive search:
version=$(mysql Varnish -B --skip-column-names -e "SELECT value FROM sys_param WHERE param='PatchLevel'" | sed -n 's/^.*\([0-9]\.[0-9]*\).*$/\1/p')
if [[ $(echo "if($version == 6.10) { print 1; } else { print 0; }" | bc) -eq 1 ]]; then
status=$(dpkg-query -l | awk '{print $2}' | grep 'sg-status-polling');
cons=$(dpkg-query -l | awk '{print $2}' | grep 'sg-consolidated-poller');
if [[ "$status" != "" && "$cons" != "" ]]; then
echo "about to change /var/www/Varnish/lib/Extra/SG/ObjectPoller2.pm"; echo;
cp /var/www/Varnish/lib/Extra/SG/ObjectPoller2.pm /var/www/Varnish/lib/Extra/SG/ObjectPoller2.pm.bkup;
sed -ir '184s!\x91\x93!\x91\x27--timeout=35\x27\x93!' /var/www/Varnish/lib/Extra/SG/ObjectPoller2.pm;
sed -n 183,185p /var/www/Varnish/lib/Extra/SG/ObjectPoller2.pm; echo;
else
echo "packages not found. Assumed to be not applicable";
fi
else
echo "This is 4.$version, skipping";
fi
The script is supposed to make sure Varnish is version 4.6.10 and has 2 custom .deb packages installed (not through apt-get). then makes a backup and edits a single line in a perl module from [] to ['--timeout=35']
it looks like its tripping up on the sed replace one liner.
There are two major problems (minor ones addressed in comments). The first is that you use the decimal code for [] instead of the hexa, so you should use \x5b\x5d instead of \x91\x93. The second problem is that if you do use the proper codes, sed will still interpret those syntactically as []. So you can't escape escaping. Here's what you should call:
sed -ri'.bkup' '184s!\[\]![\x27--timeout=35\x27]!' /var/www/Varnish/lib/Extra/SG/ObjectPoller2.pm
And this will create the backup for you (but you should double check).

If statement inside command line

I'm trying to create a shell script and the fact is, I want to change the output if the variable $output is filled. I was thinking about checking the variable with an if inside the command but I don't know if it's the correct syntax. Here is an exemple (of course that doesn't work):
ls -lisa | awk '$5 == own' own="$owner" | sort -k$column -n if [
$output ]; then print > out.txt fi
I don't know if it's going to work that way and if it's possible.
The exec built-in can change the default standard output for the rest of the running shell script. So, in this case, you would do:
if [ -n "$output" ]; then
exec >out.txt
fi
ls -lisa | awk '$5 == own' own="$owner" | sort -k$column
I'm not entirely sure what you're trying to do with the awk part, so this is just verbatim from your question.
Another option is to put the part of your script that you want to redirect into a function, and then call the function in one of two ways, redirecting the output. Example:
do_work() {
ls -lisa | awk '$5 == own' own="$owner" | sort -k$column
}
if [ -n "$output" ]; then
do_work >out.txt
else
do_work
fi
You can use the shell's "use default value" option (${variable:-default}, with /dev/stdout as the default) to do this:
ls -lisa | awk '$5 == own' own="$owner" | sort -k$column -n > "${output:-/dev/stdout}"

Extract a certain part of a string in bash with different patterns

I have this file:
CLUSTERS=SP1,SP2,SP3
FNAME_SP1="REWARDS_BTS_SP1_<GTS>.dat"
FNAME_SP2="DUMP_LOG_SP2_<GTS>.dat"
FNAME_SP3="TEST_CASE_TABLE_SP3_<GTS>.dat"
What I want to get from these are:
REWARDS_BTS_SP1_
DUMP_LOG_SP2_
TEST_CASE_TABLE_SP3_
I loop through the CLUSTERS field, get the values, and use it to find the appropriate FNAME_<CLUSTERNAME> value. Basically, the CLUSTERS value are ALWAYS before the _<GTS> part of the string. Any string pattern will do, provided that the CLUSTERS value come before the _<GTS> at the end of the string.
Any suggestions? Here's a part of the script.
function loadClusters() {
for i in `echo ${!CLUSTER*}`
do
CLUSTER=`echo ${i} | grep $1`
if [[ -n ${CLUSTER} ]]; then
CLUSTER=${!i}
break;
fi
done
echo -e ${CLUSTER}
}
function loadClustersCampaign() {
for i in `echo ${!BPOINTS*}`
do
BPOINTS=`echo ${i} | grep $1`
if [[ -n ${BPOINTS} ]]; then
BPOINTS=${!i}
break;
fi
done
for i in `echo ${!FNAME*}`
do
FNAME=`echo ${i} | grep $1`
if [[ -n ${FNAME} ]]; then
FNAME=${!i}
break;
fi
done
echo -e ${BPOINTS}"|"${FNAME}
}
#get clusters
clusters=$(loadClusters $1)
for i in `echo $clusters | sed 's/,/ /g'`
do
file=$(loadClustersCampaign ${i/-/_} | awk -F"|" '{print $2}') ;
echo $file;
#then get the part of the $file variable
done
Fun with Shell Parameter Expansions
You can use matching-prefix notation and indirect expansion to get at the variables you want, and use the "remove suffix" expansion on each result to collect just the portions of the filename that you want. For example:
FNAME_SP1='REWARDS_BTS_SP1_<GTS>.dat'
FNAME_SP2='DUMP_LOG_SP2_<GTS>.dat'
FNAME_SP3='TEST_CASE_TABLE_SP3_<GTS>.dat'
for cluster in "${!FNAME_SP#}"; do
echo ${!cluster%%<GTS>*}
done
This will print out the following:
REWARDS_BTS_SP1_
DUMP_LOG_SP2_
TEST_CASE_TABLE_SP3_
but you could issue any valid shell command inside the loop instead of using echo.
See Also
http://www.gnu.org/software/bash/manual/html_node/Shell-Parameter-Expansion.html
If you like an awk solution for this ,may be below will be useful.
> echo 'FNAME_SP1="REWARDS_BTS_SP1_<GTS>.dat"' | awk -F"<GTS>" '{split($1,a,"=\"");print substr(a[2],2)}'
REWARDS_BTS_SP1_
Furthur more detail below:
> cat temp
LUSTERS=SP1,SP2,SP3
FNAME_SP1="REWARDS_BTS_SP1_<GTS>.dat"
FNAME_SP2="DUMP_LOG_SP2_<GTS>.dat"
FNAME_SP3="TEST_CASE_TABLE_SP3_<GTS>.dat"
> awk -F"<GTS>" '/FNAME_SP/{split($1,a,"=");print substr(a[2],2)}' temp
REWARDS_BTS_SP1_
DUMP_LOG_SP2_
TEST_CASE_TABLE_SP3_
>

bash script and greping with command line

new to bash scripting so just wondering if i am doing this code right at all. im trying to search /etc/passwd and then grep and print users.
usage ()
{
echo "usage: ./file.sk user"
}
# test if we have two arguments on the command line
if [ $# != 1 ]
then
usage
exit
fi
if [[ $# < 0 ]];then
usage
exit
fi
# Search for user
fullname=`grep $1 /etc/passwd | cut -f 5 -d :`
firstname=`grep $1 /etc/passwd | cut -f 5 -d : | cut -f 1 -d " "`
#check if there. if name is founf: print msg and line entry
not sure as how to this or if im doing this right...
am i doing this right?
grep $1 /etc/passwd | while IFS=: read -r username passwd uid gid info home shell
do
echo $username: $info
done
This might work for you:
fullname=$(awk -F: '/'$1'/{print $5}' /etc/passwd)
firstname=${fullname/ *}
You're on the right track.
But I think the 2nd if [[ $# < 0 ]] .... fi block doesn't get you much. Your first test case gets the situation right, 'This script requires 1 argument or quits'.
Also, I don't see what you need firstname for, so a basic test is
case "${fullname:--1}" in
-[1] ) printf "No userID found for input=$1\n" ; exit 1 ;;
* )
# assume it is OK
# do what every you want after this case block
;;
esac
You can of course, duplicate this using "${firstname}" if you really need the check.
OR as an equivalent if ... fi is
if [[ "${fullname}" == "" ]] ; then
printf "No userID found for input=$1\n" ; exit 1
fi
note to be more efficient, you can parse ${fullname} to get firstname without all the calls to grep etc, i.e.
firstname=${fullname%% *}
Let me know if you need for me to explain :--1} and %% *} variable modifiers.
I hope this helps.
Instead of this:
fullname=`grep $1 /etc/passwd | cut -f 5 -d :`
firstname=`grep $1 /etc/passwd | cut -f 5 -d : | cut -f 1 -d " "`
Try this:
fullname=$(cut -f5 -d: /etc/passwd | grep "$1")
if [[ $? -ne 0 ]]; then
# not found, do something
fi
firstname=${fullname%% *} # remove the space and everything after
Note that I changed my answer to cut before grep so that it doesn't get false positives if some other field matches the full name you are searching for.
You can simply by reading your input to an array and then printing out your desired fields, something like this -
grep $1 /etc/passwd | while IFS=: read -a arry; do
echo ${arry[0]}:${arry[4]};
done
Test:
jaypal:~/Temp] echo "root:*:0:0:System Administrator:/var/root:/bin/sh" |
while IFS=: read -a arry; do
echo ${arry[0]}:${arry[4]};
done
root:System Administrator

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