I am trying to print out the contents of a TNS entry from the tnsnames.ora file to make sure it is correct from an Oracle RAC environment.
So if I do something like:
grep -A 4 "mydb.mydomain.com" $ORACLE_HOME/network/admin/tnsnames.ora
I will get back:
mydb.mydomain.com =
(DESCRIPTION =
(ADDRESS =
(PROTOCOL = TCP)(HOST = myhost.mydomain.com)(PORT = 1521))
(CONNECT_DATA =(SERVER = DEDICATED)(SERVICE_NAME=mydb)))
Which is what I want. Now I have an environment variable being set for the JDBC connection string by an external program when the shell script gets called like:
export $DB_URL=#myhost.mydomain.com:1521/mydb
So I need to get TNS alias mydb.mydomain.com out of the above string. I'm not sure how to do multiple matches and reorder the matches with regex and need some help.
grep #.+: $DB_URL
I assume will get the
#myhost.mydomain.com:
but I'm looking for
mydb.mydomain.com
So I'm stuck at this part. How do I get the TNS alias and then pipe/combine it with the initial grep to display the text for the TNS entry?
Thanks
update:
#mklement0 #Walter A - I tried your ways but they are not exactly what I was looking for.
echo "#myhost.mydomain.com:1521/mydb" | grep -Po "#\K[^:]*"
echo "#myhost.mydomain.com:1521/mydb" | sed 's/.*#\(.*\):.*/\1/'
echo "#myhost.mydomain.com:1521/mydb" | cut -d"#" -f2 | cut -d":" -f1
echo "#myhost.mydomain.com:1521/mydb" | tr "#:" "\t" | cut -f2
echo "#myhost.mydomain.com:1521/mydb" | awk -F'[#:]' '{ print $2 }'
All these methods get me back: myhost.mydomain.com
What I am looking for is actually: mydb.mydomain.com
Note:
- For brevity, the commands below use bash/ksh/zsh here-string syntax to send strings to stdin (<<<"$var"). If your shell doesn't support this, use printf %s "$var" | ... instead.
The following awk command will extract the desired string (mydb.mydomain.com) from $DB_URL (#myhost.mydomain.com:1521/mydb):
awk -F '[#:/]' '{ sub("^[^.]+", "", $2); print $4 $2 }' <<<"$DB_URL"
-F'[#:/]' tells awk to split the input into fields by either # or : or /. With your input, this means that the field of interest are part of the second field ($2) and the fourth field ($4). The sub() call removes the first .-based component from $2, and the print call pieces together the result.
To put it all together:
domain=$(awk -F '[#:/]' '{ sub("^[^.]+", "", $2); print $4 $2 }' <<<"$DB_URL")
grep -F -A 4 "$domain" "$ORACLE_HOME/network/admin/tnsnames.ora"
You don't strictly need intermediate variable $domain, but I've added it for clarity.
Note how -F was added to grep to specify that the search term should be treated as a literal, so that characters such as . aren't treated as regex metacharacters.
Alternatively, for more robust matching, use a regex that is anchored to the start of the line with ^, and \-escape the . chars (using shell parameter expansion) to ensure their treatment as literals:
grep -A 4 "^${domain//./\.}" "$ORACLE_HOME/network/admin/tnsnames.ora"
You can get a part of a string with
# Only GNU-grep
echo "#myhost.mydomain.com:1521/mydb" | grep -Po "#\K[^:]*"
# or
echo "#myhost.mydomain.com:1521/mydb" | sed 's/.*#\(.*\):.*/\1/'
# or
echo "#myhost.mydomain.com:1521/mydb" | cut -d"#" -f2 | cut -d":" -f1
# or, when the string already is in a var
echo "${DB_URL#*#}" | cut -d":" -f1
# or using a temp var
tmpvar="${DB_URL#*#}"
echo "${tmpvar%:*}"
I had skipped the alternative awk, that was given by #mklement0 already:
echo "#myhost.mydomain.com:1521/mydb" | awk -F'[#:]' '{ print $2 }'
The awk solution is straight-forward, when you want to use the same approach without awk you can do something like
echo "#myhost.mydomain.com:1521/mydb" | tr "#:" "\t" | cut -f2
or the ugly
echo "#myhost.mydomain.com:1521/mydb" | (IFS='#:' read -r _ url _; echo "$url")
What is happening here?
After introducing the new IFS I want to take the second word of the input. The first and third word(s) are caught in the dummy var's _ (you could have named them dummyvar1 and dummyvar2). The pipe | creates a subprocess, so you need ()to hold reading and displaying the var url in the same process.
Related
I want to Filter all content after match with the content and bring the first value after the "."
I have an output something like this:
Output:
product: 13.6.0.35_0
More specifically, I need only the first two digits and the first digit after the dot, remembering that we should not cling to the values in the issue, but rather on the method of filtering the content.
Expected:
13.6
I tried something like:
echo "product: 13.6.0.35_0" | grep -ow '\w*13\w*'
If you need to use grep with the current logic, you can use
echo "product: 13.6.0.35_0" | grep -ow '13\.[0-9]*' | head -1
where 13\.[0-9]* matches 13, . and zero or more digits (as whole word due to w option) and head -1 gets the first match.
You may also use sed or awk:
sed -En 's/.* ([0-9]+\.[0-9]+).*/\1/p' <<< "product: 13.6.0.35_0"
awk -F'[[:space:].]' '{print $2"."$3}' <<< "product: 13.6.0.35_0"
See the online demo.
The sed command matches any text up to space, then matches the space and captures the two subsequent dot-separated numbers into Group 1 (\1) and then the rest of the line is matched and replaced with Group 1 value that is printed (as the default line output is suppressed with -n).
In the awk command, the field separator is set to whitespace and . with -F'[[:space:].]' and the {print $2"."$3} part prints the second and third field values joined with a ..
A pure shell solution using the builtin read , Parameter Expansion and curly braces for command groupings.
echo "product: 13.6.0.35_0" | { read -r _ value; echo "${value%.*.*}" ; }
You can also use cut:
echo 'product: 13.6.0.35_0' | cut -d ' ' -f2 | cut -d '.' -f1-2
13.6
I reached the expected output, it's simple but it works:
var=$(echo "product: 13.6.0.35_0" | grep -Eo '[[:digit:]]+' | sed -n 1,2p)
echo ${var} | sed 's/ /./g'
.textexpandrc
[yoro] よろしくお願いします。
[ohayo] おはようございます。
元気ですか？
[otsu] お疲れさまでします。
Looking for
$ KEY=ohayo; awk "???" ~/.textexpandrc
おはようございます。
元気ですか？
awk or sed is fine, but I'd like to avoid using a mix of awk/sed/perl/tr/cut etc because I'm under the impression that awk is robust enough to handle this on its own.
The best I could find on my own was
$ KEY=ohayo; awk "/\[${KEY}/,/\[otsu/" ~/.textexpandrc | sed "s/\[${KEY}\] //" | grep -v otsu
おはようございます。
元気ですか？
But I need to know the next key in advance (not impossible but ugly). Strangely, if asking awk to search until the square bracket, it fails to select a multiline
$ KEY=ohayo; awk "/\[${KEY}/,/\[/" ~/.textexpandrc
[ohayo] おはようございます。
Currently using a single-line parser solution as follow
#!/usr/bin/env bash
CONFIG=${HOME}/.textexpandrc
ALL_KEYS=$(sed 's/\].*/]/' ${CONFIG} | tr -d '[]')
KEY=$(echo $ALL_KEYS | rofi -sep ' ' -dmenu -p "autocomplete")
grep "\[${KEY}\]" $CONFIG | sed "s/\[${KEY}\] //" | xsel -ib # ← HERE
xdotool key ctrl+shift+v
If you set up the RS and FS variables to match [ and ], this works quite well:
awk 'BEGIN{ RS="\["; FS="\] " }; $1 ~ key { print $2 }' key=ohayo tmp.txt
You pass in the parameter you're searching for using key=.... on the command line instead of setting a variable. This makes it much easier to write the awk script within single quotes.
I have text like:
TEXT="I need to replace the hostname [[google.com]] with it's ip in side the text"
Is there a way to use something like below, but working?
sed -Ee "s/\[\[(.*)\]\]/`host -t A \1 | rev | cut -d " " -f1 | rev`/g" <<< $TEXT
looks like the value of \1 is not being passed to the shell command used inside sed.
Thanks
Backquote interpolation is performed by the shell, not by sed. This means that your backquotes will either be replaced by the output of a command before the sed command is run, or (if you correctly quote them) they will not be replaced at all, and sed will see the backquotes.
You appear to be trying to have sed perform a replacement, then have the shell perform backquote interpolation.
You can get the backquotes past the shell by quoting them properly:
$ echo "" | sed -e 's/^/`hostname`/'
`hostname`
However, in that case you will have to use the resulting string in a shell command line to cause backquote interpolation again.
Depending on how you feel about awk, perl, or python, I'd suggest you use one of them to do this job in a single pass. Alternatively, you could make a first pass extracting the hostnames into a command without backquotes, then execute the commands to get the IP addresses you want, then replace them in another pass.
It's got to be a two part command, one to get a variable that bash can use, the other to do a straight-up /s/ replacement with sed.
TEXT="I need to replace the hostname [[google.com]] with it's ip in side the text"
DOMAIN=$(echo $TEXT | sed -e 's/^.*\[\[//' -e 's/\]\].*$//')
echo $TEXT | sed -e 's/\[\[.*\]\]/'$(host -tA $DOMAIN | rev | cut -d " " -f1 | rev)'/'
But, more cleanly using how to split a string in shell and get the last field
TEXT="I need to replace the hostname [[google.com]] with it's ip in side the text"
DOMAIN=$(echo $TEXT | sed -e 's/^.*\[\[//' -e 's/\]\].*$//')
HOSTLOOKUP=$(host -tA $DOMAIN)
echo $TEXT | sed -e 's/\[\[.*\]\]/'${HOSTLOOKUP##* }/
The short version is that you can't mix sed and bash the way you're expecting to.
This works:
#!/bin/bash
txt="I need to replace the hostname [[google.com]] with it's ip in side the text"
host_name=$(sed -E 's/^[^[]*\[\[//; s/^(.*)\]\].*$/\1/' <<<"$txt")
ip_addr=$(host -tA "$host_name" | sed -E 's/.* ([0-9.]*)$/\1/')
echo "$txt" | sed -E 's/\[\[.*\]\]/'"$ip_addr/"
# I need to replace the hostname 172.217.4.174 with it's ip in side the text
Thank you all,
I made the below solution:
function host_to_ip () {
echo $(host -t A $1 | head -n 1 | rev | cut -d" " -f1 | rev)
}
function resolve_hosts () {
local host_placeholders=$(grep -o -e "##.*##" $1)
for HOST in ${host_placeholders[#]}
do
sed -i -e "s/$HOST/$(host_to_ip $(sed -Ee 's/##(.*)##/\1/g' <<< $HOST))/g" $1
done
}
Where resolve_hosts gets a text file as an argument
I try to grep the (write access) password from .my.cnf, but I didnt get it yet.
The .my.cnf looks like this:
# longer
# comment text
[clientreadonly]
password=pass1 # comment
port=3306
user=test_ro
socket=/var/lib/mysql/mysql.sock
[client]
password=pass2 # comment
port=3306
user=test
socket=/var/lib/mysql/mysql.sock
and I want to grep pass2. and the code shouldnt be too verbose of course. I ended up with
grep 'password=' ~/.my.cnf | sed -e 's/password=//
but thath actually leaves the #comment behind the pass2 and I dont want to replace the whole comment (because its long in the original and stupid to just replace it). So I would need a regex to somehow get the pass2 only.
The main target is, to grep the password so I can easily use it in a shell command line
$ awk -F'[= ]' '/^password=/ && p !~ /clientreadonly/{print $2} {p=$0}' ~/.my.cnf
pass2
-F'[= ]' use space or = as field separator
/^password=/ && p !~ /clientreadonly/ if line starts with password= and previous line doesn't contain clientreadonly
print $2 print the second field
p=$0 save the previous line in p variable
You can modify little bit like the following -
grep 'password=' ~/.my.cnf | sed -e 's/password=//' -e 's/ # comment//'
or other way -
grep 'password=' ~/.my.cnf | cut -d' ' -f1 | cut -d'=' -f2
Using perl:
perl -00 -ane '/\[client\].password=(\S+)/s && print $1' < ~/.my.cnf
Output:
pass2
I want to find the string in that is placed with in the brackets. How do I use sed to pull the string?
# cat /sys/block/sdb/queue/scheduler
noop anticipatory deadline [cfq]
I'm not getting the exact result
# cat /sys/block/sdb/queue/scheduler | sed 's/\[*\]//'
noop anticipatory deadline [cfq
I'm expecting an output
cfq
It can be easier with grep, if it happens to be changing the position in which the text in between brackets is located:
$ grep -Po '(?<=\[)[^]]*' file
cfq
This is look-behind: whenever you find a string [, start fetching all the characters up to a ].
See another example:
$ cat a
noop anticipatory deadline [cfq]
hello this [is something] we want to [enclose] yeah
$ grep -Po '(?<=\[)[^]]*' a
cfq
is something
enclose
You can also use awk for this, in case it is always in the same position:
$ awk -F[][] '{print $2}' file
cfq
It is setting the field separators as [ and ]. And from that, prints the second one.
And with sed:
$ sed 's/[^[]*\[\([^]]*\).*/\1/g' file
cfq
It is a bit messy, but basically it is looking from the block of text in between [] and prints it back.
I found one possible solution-
cut -d "[" -f2 | cut -d "]" -f1
so the exact solution is
# cat /sys/block/sdb/queue/scheduler | cut -d "[" -f2 | cut -d "]" -f1
Another potential solution is awk:
s='noop anticipatory deadline [cfq]'
awk -F'[][]' '{print $2}' <<< "$s"
cfq
Another way by gnu grep :
grep -Po "\[\K[^]]*" file
with pure shell:
while read line; do [[ "$line" =~ \[([^]]*)\] ]] && echo "${BASH_REMATCH[1]}"; done < file
Another awk
echo 'noop anticipatory deadline [cfq]' | awk '{gsub(/.*\[|\].*/,x)}8'
cfq
perl -lne 'print $1 if(/\[([^\]]*)\]/)'
Tested here