I'm writing my function to replace an effective option in a file to my setting.
The 1.txt is like:
PasswordAuthentication yes
PermitRootLogin yes
My function will process the file then output like:
#PasswordAuthentication yes
PasswordAuthentication no
#PermitRootLogin yes
PermitRootLogin no
The sed parameter is from a string generated by the function,sed_chain(), like below:
The problem is if there's space between ${pattern} and ${option}, then I got error:
sed: -e expression #1, char 46: unterminated `s' command
If there's no space between them, the function works, but it's not what I want.
#!/bin/bash
A="PasswordAuthentication no"
B="PermitRootLogin no"
F="/tmp/1.txt"
sed_chain() {
args=("$#")
file=${#:(-1)}
pattern_params=""
for i in $(seq 0 $(($#-2)))
do
pattern=$(echo ${args[$i]}|cut -d" " -f1)
option=$(echo ${args[$i]}|cut -d" " -f2)
echo $pattern
echo $option
pattern_params="-e s/^[^#]*${pattern}.*$/#&\n${pattern} ${option}/g $pattern_params" # failed
#pattern_params='-e s/^[^#]*'${pattern}'.*$/#&'"\n${pattern}${option}"'/g '${pattern_params} # passed
echo "*** $pattern_params ***"
done
sed $pattern_params $file
}
sed_chain "$A" "$B" "$F"
Try wrapping single-quotes around the expression.
pattern_params="-e 's/^[^#]*${pattern}.*$/#&\n${pattern} ${option}/g' $pattern_params"
I have a workaround, instead of combining all of the parameter into one, I run sed command one by one for each parameter. It works fine. However I still want to know how to combine the parameters into one.
sed_chain() {
args=("$#")
file=${#:(-1)}
for i in $(seq 0 $(($#-2)))
do
pattern=$(echo ${args[$i]}|cut -d" " -f1)
option=$(echo ${args[$i]}|cut -d" " -f2)
echo $pattern
echo $option
pattern_param="s/^[^#]*${pattern}.*$/#&\n${pattern} ${option}/g"
sed -i -e "$pattern_param" $file
done
}
Does this
[[:space:]]
perhaps work?
Related
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 have some basic knowledge on using regular expressions with grep (bash).
But I want to use regular expressions the other way around.
For example I have a file containing the following entries:
line_one=[0-3]
line_two=[4-6]
line_three=[7-9]
Now I want to use bash to figure out to which line a particular number matches.
For example:
grep 8 file
should return:
line_three=[7-9]
Note: I am aware that the example of "grep 8 file" doesn't make sense, but I hope it helps to understand what I am trying to achieve.
Thanks for you help,
Marcel
As others haven pointed out, awk is the right tool for this:
awk -F'=' '8~$2{print $0;}' file
... and if you want this tool to feel more like grep, a quick bash wrapper:
#!/bin/bash
awk -F'=' -v seek_value="$1" 'seek_value~$2{print $0;}' "$2"
Which would run like:
./not_exactly_grep.sh 8 file
line_three=[7-9]
My first impression is that this is not a task for grep, maybe for awk.
Trying to do things with grep I only see this:
for line in $(cat file); do echo 8 | grep "${line#*=}" && echo "${line%=*}" ; done
Using while for file reading (following comments):
while IFS= read -r line; do echo 8 | grep "${line#*=}" && echo "${line%=*}" ; done < file
This can be done in native bash using the syntax [[ $value =~ $regex ]] to test:
find_regex_matching() {
local value=$1
while IFS= read -r line; do # read from input line-by-line
[[ $line = *=* ]] || continue # skip lines not containing an =
regex=${line#*=} # prune everything before the = for the regex
if [[ $value =~ $regex ]]; then # test whether we match...
printf '%s\n' "$line" # ...and print if we do.
fi
done
}
...used as:
find_regex_matching 8 <file
...or, to test it with your sample input inline:
find_regex_matching 8 <<'EOF'
line_one=[0-3]
line_two=[4-6]
line_three=[7-9]
EOF
...which properly emits:
line_three=[7-9]
You could replace printf '%s\n' "$line" with printf '%s\n' "${line%%=*}" to print only the key (contents before the =), if so inclined. See the bash-hackers page on parameter expansion for a rundown on the syntax involved.
This is not built-in functionality of grep, but it's easy to do with awk, with a change in syntax:
/[0-3]/ { print "line one" }
/[4-6]/ { print "line two" }
/[7-9]/ { print "line three" }
If you really need to, you could programmatically change your input file to this syntax, if it doesn't contain any characters that need escaping (mainly / in the regex or " in the string):
sed -e 's#\(.*\)=\(.*\)#/\2/ { print "\1" }#'
As I understand it, you are looking for a range that includes some value.
You can do this in gawk:
$ cat /tmp/file
line_one=[0-3]
line_two=[4-6]
line_three=[7-9]
$ awk -v n=8 'match($0, /([0-9]+)-([0-9]+)/, a){ if (a[1]<n && a[2]>n) print $0 }' /tmp/file
line_three=[7-9]
Since the digits are being treated as numbers (vs a regex) it supports larger ranges:
$ cat /tmp/file
line_one=[0-3]
line_two=[4-6]
line_three=[75-95]
line_four=[55-105]
$ awk -v n=92 'match($0, /([0-9]+)-([0-9]+)/, a){ if (a[1]<n && a[2]>n) print $0 }' /tmp/file
line_three=[75-95]
line_four=[55-105]
If you are just looking to interpret the right hand side of the = as a regex, you can do:
$ awk -F= -v tgt=8 'tgt~$2' /tmp/file
You would like to do something like
grep -Ef <(cut -d= -f2 file) <(echo 8)
This wil grep what you want but will not display where.
With grep you can show some message:
echo "8" | sed -n '/[7-9]/ s/.*/Found it in line_three/p'
Now you would like to transfer your regexp file into such commands:
sed 's#\(.*\)=\(.*\)#/\2/ s/.*/Found at \1/p#' file
Store these commands in a virtual command file and you will have
echo "8" | sed -nf <(sed 's#\(.*\)=\(.*\)#/\2/ s/.*/Found at \1/p#' file)
I have a string something like this
xsd:import schemaLocation="AppointmentManagementService.xsd6.xsd" namespace=
I want to extract the following from it :
AppointmentManagementService.xsd6.xsd
I have tried using regex, bash and sed with no success. Can someone please help me out with this?
The regex that I used was this :
/AppointmentManagementService.xsd\d{1,2}.xsd/g
Your string is:
nampt#nampt-desktop:$ cat 1
xsd:import schemaLocation="AppointmentManagementService.xsd6.xsd" namespace=
Try with awk:
cat 1 | awk -F "\"" '{print $2}'
Output:
AppointmentManagementService.xsd6.xsd
sed doesn't recognize \d, use [0-9] or [[:digit:]] instead:
sed 's/^.*schemaLocation="\([^"]\+[[:digit:]]\{1,2\}\.xsd\)".*$/\1/g'
## or
sed 's/^.*schemaLocation="\([^"]\+[0-9]\{1,2\}\.xsd\)".*$/\1/g'
You can use bash native regex matching:
$ in='xsd:import schemaLocation="AppointmentManagementService.xsd6.xsd" namespace='
$ if [[ $in =~ \"(.+)\" ]]; then echo "${BASH_REMATCH[1]}"; fi
Output:
AppointmentManagementService.xsd6.xsd
Based on your example, if you want to grant, at least, 1 or, at most, 2 digits in the .xsd... component, you can fine tune the regex with:
$ if [[ $in =~ \"(AppointmentManagementService.xsd[0-9]{1,2}.xsd)\" ]]; then echo "${BASH_REMATCH[1]}"; fi
using PCRE in GNU grep
grep -oP 'schemaLocation="\K.*?(?=")'
this will output pattern matched between schemaLocation=" and very next occurrence of "
Reference:
https://unix.stackexchange.com/a/13472/109046
Also we can use 'cut' command for this purpose,
[root#code]# echo "xsd:import schemaLocation=\"AppointmentManagementService.xsd6.xsd\" namespace=" | cut -d\" -f 2
AppointmentManagementService.xsd6.xsd
s='xsd:import schemaLocation="AppointmentManagementService.xsd6.xsd" namespace='
echo $s | sed 's/.*schemaLocation="\(.*\)" namespace=.*/\1/'
I have a path such as thus ..
/Users/me/bla/dev/trunk/source/java/com/mecorp/sub/misc/filename.java
I'd like to be able to use bash to create the package structure in another dir somewhere e.g.
com/mecorp/sub/misc/
I tried the following but it wont work .. I was able to get a match if I change my regex to .* so that implies my bash is ok - There must be something wrong with the way im quoting the regex or maybe the regex its self. I do see working here ..
http://regexr.com?3439m
So im confused ?
regex="(?<=/java)(.*)(?=/)"
[[ $fullfile =~ $regex ]]
echo "pkg name " ${BASH_REMATCH[0]}
Thanks for your time.
EDIT - I'm using OSX so it doesn't have all those nice spiffy GNU extensions.
Try this :
using GNU grep :
$ echo '/Users/me/bla/dev/trunk/source/java/com/mecorp/sub/misc/filename.java' |
grep -oP 'java/\K.*/'
com/mecorp/sub/misc/
See http://regexr.com?3439p
Or using bash :
x="/Users/me/bla/dev/trunk/source/java/com/mecorp/sub/misc/filename.java"
[[ $x =~ java/(.*/) ]] && echo ${BASH_REMATCH[1]}
Or with awk :
echo "$x" | awk -F/ '{print gensub(".*/java/(.*/).*", "\\1", $0)}'
Or with sed :
echo "$x" | sed -e 's#.*/java/\(.*/\).*#\1#'
If you try to extract the path after /java/ you can do it with this:
path=/Users/me/bla/dev/trunk/source/java/com/mecorp/sub/misc/filename.java
package=`echo $path | sed -r 's,^.*/java/(.*/).*$,\1,'`
I am trying to write a regex expression to replace one or more '+' symbols present in a file with a space. I tried the following:
echo This++++this+++is+not++done | awk '{ sub(/\++/, " "); print }'
This this+++is+not++done
Expected:
This this is not done
Any ideas why this did not work?
Use gsub which does global substitution:
echo This++++this+++is+not++done | awk '{gsub(/\++/," ");}1'
sub function replaces only 1st match, to replace all matches use gsub.
Or the tr command:
echo This++++this+++is+not++done | tr -s '+' ' '
The idiomatic awk solution would be just to translate the input field separator to the output separator:
$ echo This++++this+++is+not++done | awk -F'++' '{$1=$1}1'
This this is not done
Try this
echo "This++++this+++is+not++done" | sed -re 's/(\+)+/ /g'
You could use sed too.
echo This++++this+++is+not++done | sed -e 's/+\{1,\}/ /g'
This matches one or more + and replaces it with a space.
For this case I recommend sed, this is powerful for substitution and has a short syntax.
Solution sed:
echo This++++this+++is+not++done | sed -En 's/\\++/ /gp'
Result:
This this is not done
For awk:
You must use the gsub function for global line substitution (more than one substitution).
The syntax:
gsub(regexp, replacement [, target]).
If the third parameter is ommited then $0 is the target.
Target must a variable or array element. gsub works in target, overwritten target with the replacement.
Solution awk:
echo This++++this+++is+not++done | awk 'gsub(/\\++/," ")
Result:
This this is not done
echo "This++++this+++is+not++done" | sed 's/++*/ /g'
If you have access to node on your computer you can do it by installing rexreplace
npm install -g regreplace
and then run
rexreplace '\++' ' ' myfile.txt
Of if you have more files in a dir data you can do
rexreplace '\++' ' ' data/*.txt