How to parse file to commands in bash - bash

I'm trying to achieve some goal here and while I do know partials steps, I am not successful in putting it all together. I'm looking for an inline command for single usage on multiple hosts. Let's have SW repository file organized like this:
# comments
PROD_NAME:INSTALL_DIR:OPTIONS
PROD_NAME:INSTALL_DIR:OPTIONS
PROD_NAME:INSTALL_DIR:OPTIONS
Now, let's say we want to process the file and do some copy action on every one of the products. So, I can pipe grep getting rid of comment lines into while do cycle, where I use awk to break down each line to product name and it's path and complete it into copy commands. And that's too much of nesting for my skill level, I'm afraid. Anyone who'd care to share?

you can use a bash loop to do the same
$ while IFS=: read -r p i o;
do echo "cp $o $p $i";
done < <(grep -v '^#' file)
cp OPTIONS PROD_NAME INSTALL_DIR
cp OPTIONS PROD_NAME INSTALL_DIR
cp OPTIONS PROD_NAME INSTALL_DIR
remove echo to run as given.

Comments can be removed by
grep -v '^#'
For awk you have to specify the field delimiter:
awk -f: '{print $1, $2, $3}'
In order to craft copy commands you have to pipe the result to a shell.
echo -e '# comments\nNAME:DIR:OPT' |
grep -v '^#' |
awk -F: '{print "cp", $3, $2, $1}' |
sh
Even better: read a book.
Or this:
http://linuxcommand.org/learning_the_shell.php
https://en.wikibooks.org/wiki/Bourne_Shell_Scripting

Related

give a file without changing the name in script [duplicate]

This question already has answers here:
How to pass parameters to a Bash script?
(4 answers)
Closed 1 year ago.
At the beginning I have a file.txt, which contains several informations that I will take using the grep command as you see in the script.
What I want is to give the script the file I want instead of file.txt but without changing the file name each time in the script for example if the file is named Me.txt I don’t want to go into the script and write Me.txt in each grep command especially if I have dozens of orders.
Is there a way to do this?
#!/bin/bash
grep teste file.txt > testline.txt
awk '{print $2}' testline.txt > test.txt
echo '#'
echo '#'
grep remote file.txt > remoteline.txt
awk '{print $3}' remoteline.txt > remote.txt
echo '#'
echo '#'
grep adresse file.txt > adresseline.txt
awk '{print $2}' adresseline.txt > adresse.txt
Using a parameter, as many contributors here suggested, is of course the obvious approach, and the one which is usually taken in such case, so I want to extend this idea:
If you do it naively as
filename=$1
you have to supply the name on every invocation. You can improve on this by providing a default value for the case the parameter is missing:
filename=${1:-file.txt}
But sometimes you are in a situation, where for some time (working on a specific task), you always need the same filename over and over, and the default value happens to be not the one you need. Another possibility to pass information to a program is via the environment. If you set the filename by
filename=${MOOFOO:-file.txt}
it means that - assuming your script is called myscript.sh - if you invoke your script by
MOOFOO=myfile.txt myscript.sh
it uses myfile.txt, while if you call it by
myscript.sh
it uses the default file.txt. You can also set MOOFOO in your shell, as
export MOOFOO=myfile.txt
and then, even a lone execution of
myscript.sh
with use myfile.txt instead of the default file.txt
The most flexible approach is to combine both, and this is what I often do in such a situation. If you do in your script a
filename=${1:-${MOOFOO:-file.txt}}
it takes the name from the 1st parameter, but if there is no parameter, takes it from the variable MOOFOO, and if this variable is also undefined, uses file.txt as the last fallback.
You should pass the filename as a command line parameter so that you can call your script like so:
script <filename>
Inside the script, you can access the command line parameters in the variables $1, $2,.... The variable $# contains the number of command line parameters passed to the script, and the variable $0 contains the path of the script itself.
As with all variables, you can choose to put the variable name in curly brackets which has advantages sometimes: ${1}, ${2}, ...
#!/bin/bash
if [ $# = 1 ]; then
filename=${1}
else
echo "USAGE: $(basename ${0}) <filename>"
exit 1
fi
grep teste "${filename}" > testline.txt
awk '{print $2}' testline.txt > test.txt
echo '#'
echo '#'
grep remote "${filename}" > remoteline.txt
awk '{print $3}' remoteline.txt > remote.txt
echo '#'
echo '#'
grep adresse "${filename}" > adresseline.txt
awk '{print $2}' adresseline.txt > adresse.txt
By the way, you don't need two different files to achieve what you want, you can just pipe the output of grep straight into awk, e.g.:
grep teste "${filename}" | awk '{print $2}' > test.txt
but then again, awk can do the regex match itself, reducing it all to just one command:
awk '/teste/ {print $2}' "${filename}" > test.txt

Extract nth column from a variable

i have a variable Firstline with value FHEAD,0000000001,STKU,20150927000000,201509270000000000,1153,,0000000801,W from which i need 5th field alone.
Can any one help me to resolve this.
I have used the below command but it is giving me an error
echo "FHEAD,0000000001,STKU,20150927000000,201509270000000000,1153,,0000000801,W" | awk -f ',' '{print $5}'
awk: fatal: can't open source file
,' for reading (No such file or directory)
As you tag it as bash and not awk (which is also a valid solution), you can do
IFS=, read -a a <<< "FHEAD,0000000001,STKU,20150927000000,201509270000000000,1153,,0000000801,W"
echo ${a[4]}
to obtain the same result without spawning a new process (note that bash arrays are 0-based).
Try -F not -f.
-F is for the field separator
-f is for the filename of the awk program.
You can use sed too
echo "..." | sed -E 's/([^,]*,){4}([^,]*).*/\2/'

redirect output of loop to current reading file

I have simple script that looks like
for file in `ls -rlt *.rules | awk '{print $9}'`
do
cat $file | awk -F"|" -v DATE=$(date +%Y"_"%m"_"%d) '!$3{$3=DATE} !$4{$4=DATE} 1' OFS="|" $file
done
How can i redirect output of awk to the same file which it is reading to perform action.
files have data before running above script
123|test||
After running script files should have data like
123|test|2017_04_05|2017_04_05
You cannot replace your files on the fly like this, mostly because you increase their size.
The way is to use temporary file, then replace the current:
for file in `ls -1 *.rules `
do
TMP_FILE=/tmp/${file}_$$
awk -F"|" -v DATE=$(date +%Y"_"%m"_"%d) '!$3{$3=DATE} !$4{$4=DATE} 1' OFS="|" $file > ${TMP_FILE}
mv ${TMP_FILE} $file
done
I would modify Michael Vehrs otherwise good answer as follows:
ls -rt *.rules | while read file
do
TMP_FILE="/tmp/${file}_$$"
awk -F"|" -v DATE=$(date +%Y"_"%m"_"%d) \
'!$3{$3=DATE} !$4{$4=DATE} 1' OFS="|" "$file" > "$TMP_FILE"
mv "$TMP_FILE" "$file"
done
Your question uses ls(1) to sort the files by time, oldest first. The above preserves that property. I removed the {} braces because they add nothing in a shell script if the variable name isn't being interpolated, and quotes to cope with filenames that include whitespace.
If time-order doesn't matter, I'd consider an inside-out solution: in awk, write to a temporary file instead of standard output, and then rename it with system in an END block. Then if something goes wrong your input is preserved.
First of all, it is silly to use a combination of ls -rlt and awk when the only thing you need is the file name. You don't even need ls because the shell glob is expanded by the shell, not ls. Simply use for file in *.rules. Since the date would seem to be the same for every file (unless you run the command at midnight), it is sufficient to calculate it in advance:
date=$(date +%Y"_"%m"_"%d)
for file in *.rules
do
TMP_FILE=$(mktemp ${file}_XXXXXX)
awk -F"|" -v DATE=${date} '!$3{$3=DATE} !$4{$4=DATE} 1' OFS="|" $file > ${TMP_FILE}
mv ${TMP_FILE} $file
done
However, since awk also knows which file it is reading, you could do something like this:
awk -F"|" -v DATE=$(date +%Y"_"%m"_"%d) \
'!$3{$3=DATE} !$4{$4=DATE} { print > FILENAME ".tmp" }' OFS="|" *.rules
rename .tmp "" *.rules.tmp

grep: compare string from file with another string

I have a list of files paths that I need to compare with a string:
git_root_path=$(git rev-parse --show-toplevel)
list_of_files=.git/ForGeneratingSBConfigAlert.txt
cd $git_root_path
echo "These files needs new OSB config:"
while read -r line
do
modfied="$line"
echo "File for compare: $modfied"
if grep -qf $list_of_files" $modfied"; then
echo "Found: $modfied"
fi
done < <(git status -s | grep -v " M" | awk '{if ($1 == "M") print $2}')
$modified - is a string variable that stores path to file
Pattern file example:
SVCS/resources/
SVCS/bus/projects/busCallout/
SVCS/bus/projects/busconverter/
SVCS/bus/projects/Resources/ (ignore .jar)
SVCS/bus/projects/Teema/
SVCS/common/
SVCS/domain/
SVCS/techutil/src/
SVCS/tech/mds/src/java/fi/vr/h/service/tech/mds/exception/
SVCS/tech/mds/src/java/fi/vr/h/service/tech/mds/interfaces/
SVCS/app/cashmgmt/src/java/fi/vr/h/service/app/cashmgmt/exception/
SVCS/app/cashmgmt/src/java/fi/vr/h/service/app/cashmgmt/interfaces/
SVCS/app/customer/src/java/fi/vr/h/service/app/customer/exception/
SVCS/app/customer/src/java/fi/vr/h/service/app/customer/interfaces/
SVCS/app/etravel/src/java/fi/vr/h/service/app/etravel/exception/
SVCS/app/etravel/src/java/fi/vr/h/service/app/etravel/interfaces/
SVCS/app/hermes/src/java/fi/vr/h/service/app/hermes/exception/
SVCS/app/hermes/src/java/fi/vr/h/service/app/hermes/interfaces/
SVCS/app/journey/src/java/fi/vr/h/service/app/journey/exception/
SVCS/app/journey/src/java/fi/vr/h/service/app/journey/interfaces/
SVCS/app/offline/src/java/fi/vr/h/service/app/offline/exception/
SVCS/app/offline/src/java/fi/vr/h/service/app/offline/interfaces/
SVCS/app/order/src/java/fi/vr/h/service/app/order/exception/
SVCS/app/order/src/java/fi/vr/h/service/app/order/interfaces/
SVCS/app/payment/src/java/fi/vr/h/service/app/payment/exception/
SVCS/app/payment/src/java/fi/vr/h/service/app/payment/interfaces/
SVCS/app/price/src/java/fi/vr/h/service/app/price/exception/
SVCS/app/price/src/java/fi/vr/h/service/app/price/interfaces/
SVCS/app/product/src/java/fi/vr/h/service/app/product/exception/
SVCS/app/product/src/java/fi/vr/h/service/app/product/interfaces/
SVCS/app/railcar/src/java/fi/vr/h/service/app/railcar/exception/
SVCS/app/railcar/src/java/fi/vr/h/service/app/railcar/interfaces/
SVCS/app/reservation/src/java/fi/vr/h/service/app/reservation/exception/
SVCS/app/reservation/src/java/fi/vr/h/service/app/reservation/interfaces/
kraken_test.txt
namaker_test.txt
shmaker_test.txt
I need to compare file search pattern with a string, is it possible using grep?
I'm not sure I understand the overall logic, but a few immediate suggestions come to mind.
You can avoid grep | awk in the vast majority of cases.
A while loop with a grep on a line at a time inside the loop is an antipattern. You probably just want to run one grep on the whole input.
Your question would still benefit from an explanation of what you are actually trying to accomplish.
cd "$(git rev-parse --show-toplevel)"
git status -s | awk '!/ M/ && $1 == "M" { print $2 }' |
grep -Fxf .git/ForGeneratingSBConfigAlert.txt
I was trying to think of a way to add back your human-readable babble, but on second thought, this program is probably better without it.
The -x option to grep might be wrong, depending on what you are really hoping to accomplish.
This should work:
git status -s | grep -v " M" | awk '{if ($1 == "M") print $2}' | \
grep --file=.git/ForGeneratingSBConfigAlert.txt --fixed-strings --line-regexp
Piping the awk output directly to grep avoids the while loop entirely. In most cases you'll find you don't really need to print debug messages and the like in it.
--file takes a file with one pattern to match per line.
--fixed-strings avoids treating any characters in the patterns as special.
--line-regexp anchors the patterns so that they only match if a full line of input matches one of the patterns.
All that said, could you clarify what you are actually trying to accomplish?

awk for different delimiters piped from xargs command

I run an xargs command invoking bash shell with multiple commands. I am unable to figure out how to print two columns with different delimiters.
The command is ran is below
cd /etc/yp
cat "$userlist" | xargs -I {} bash -c "echo -e 'For user {} \n'
grep -w {} auto_*home|sed 's/:/ /' | awk '{print \$1'\t'\$NF}'
grep -w {} passwd group netgroup |cut -f1 -d ':'|sort|uniq;echo -e '\n'"
the output I get is
For user xyz
auto_homeabc.jkl.com:/rtw2kop/xyz
group
netgroup
passwd
I need a tab after the auto_home(since it is a filename) like in
auto_home abc.jkl.com:/rtw2kop/xyz
The entry from auto_home file is below
xyz -rw,intr,hard,rsize=32768,wsize=32768 abc.jkl.com:/rtw2kop/xyz
How do I awk for the first field(auto_home) and the last field abc.jkl.com:/rtw2kop/xyz? As I have put a pipe from grep command to awk.'\t' isnt working in the above awk command.
If I understand what you are attempting correctly, then I suggest this approach:
while read user; do
echo "For user $user"
awk -v user="$user" '$1 == user { print FILENAME "\t" $NF }' auto_home
awk -F: -v user="$user" '$1 == user { print FILENAME; exit }' passwd group netgroup | sort -u
done < "$userlist"
The basic trick is the read loop, which will read a line into the variable $user from the file named in $userlist; after that, it's all straightforward awk.
I took the liberty of changing the selection criteria slightly; it looked as though you wanted to select for usernames, not strings anywhere in the line. This way, only lines will be selected in which the first token is equal to the currently inspected user, and lines in which other tokens are equal to the username but not the first are discarded. I believe this to be what you want; if it is not, please comment and we can work it out.
In the 1st awk command, double-escape the \t to \\t. (You may also need to double-escape the \n.)

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