I have a properties file test.properties and it contents are as follows:
x.T1 = 125
y.T2 = 256
z.T3 = 351
How can I assign the value of y.T2 (256) to some variable within shell script and echo this value?
Check this, will help exactly:
expVal=`cat test.properties | grep "y.T2" | cut -d'=' -f2`
You want to use read in a loop in your script. While you can source a file, it doesn't work if there are spaces surrounding the = sign. Here is a way to handle reading the file:
#!/bin/sh
# test for required input filename
if [ ! -r "$1" ]; then
printf "error: insufficient input or file not readable. Usage: %s property_file\n" "$0"
exit 1
fi
# read each line into 3 variables 'name, es, value`
# (the es is just a junk variable to read the equal sign)
# test if '$name=y.T2' if so use '$value'
while read -r name es value; do
if [ "$name" == "y.T2" ]; then
myvalue="$value"
fi
done < "$1"
printf "\n myvalue = %s\n\n" "$myvalue"
Output
$ sh read_prop.sh test.properties
myvalue = 256
I know this is an old question, but I just came across this and if I understand correctly, the question is to get value for a specific key from the properties file.
Why not just use grep to find the key and awk to get the value?
Use grep and awk to extract the value from test.properties
export yT2=$(grep -iR "^y.T2" test.properties | awk -F "=" '{print $2}')
echo y.T2=$yT2
This value will contain space if there's one after the '='. Trim the leading whitespace
yT2="${yT2#"${yT2%%[![:space:]]*}"}"
Reference for trim:
How to trim whitespace from a Bash variable?.
Explanation available at reference link.
Related
I'm relatively new to bash scripting and I would like someone to explain this properly, thank you. Here is my code:
#! /bin/bash
echo "first arg: $1"
echo "first arg: $2"
var="$( grep -rnw $1 -e $2 | cut -d ":" -f1 )"
var2=$( grep -rnw $1 -e $2 | cut -d ":" -f1 | awk '{print substr($0,length,1)}')
echo "$var"
echo "$var2"
The problem I have is with the output, the script I'm trying to write is a c++ function searcher, so upon launching my script I have 2 arguments, one for the directory and the second one as the function name. This is how my output looks like:
first arg: Projekt
first arg: iseven
Projekt/AX/include/ax.h
Projekt/AX/src/ax.cpp
h
p
Now my question is: how do can I save the line by line output as a variable, so that later on I can use var as a path, or to use var2 as a character to compare. My plan was to use IF() statements to determine the type, idea: IF(last_char == p){echo:"something"}What I've tried was this question: Capturing multiple line output into a Bash variable and then giving it an array. So my code looked like: "${var[0]}". Please explain how can I use my line output later on, as variables.
I'd use readarray to populate an array variable just in case there's spaces in your command's output that shouldn't be used as field separators that would end up messing up foo=( ... ). And you can use shell parameter expansion substring syntax to get the last character of a variable; no need for that awk bit in your var2:
#!/usr/bin/env bash
readarray -t lines < <(printf "%s\n" "Projekt/AX/include/ax.h" "Projekt/AX/src/ax.cpp")
for line in "${lines[#]}"; do
printf "%s\n%s\n" "$line" "${line: -1}" # Note the space before the -1
done
will display
Projekt/AX/include/ax.h
h
Projekt/AX/src/ax.cpp
p
Suppose I have a Unix shell variable as below
variable=abc,def,ghij
I want to extract all the values (abc, def and ghij) using a for loop and pass each value into a procedure.
The script should allow extracting arbitrary number of comma-separated values from $variable.
Not messing with IFS
Not calling external command
variable=abc,def,ghij
for i in ${variable//,/ }
do
# call your procedure/other scripts here below
echo "$i"
done
Using bash string manipulation http://www.tldp.org/LDP/abs/html/string-manipulation.html
You can use the following script to dynamically traverse through your variable, no matter how many fields it has as long as it is only comma separated.
variable=abc,def,ghij
for i in $(echo $variable | sed "s/,/ /g")
do
# call your procedure/other scripts here below
echo "$i"
done
Instead of the echo "$i" call above, between the do and done inside the for loop, you can invoke your procedure proc "$i".
Update: The above snippet works if the value of variable does not contain spaces. If you have such a requirement, please use one of the solutions that can change IFS and then parse your variable.
If you set a different field separator, you can directly use a for loop:
IFS=","
for v in $variable
do
# things with "$v" ...
done
You can also store the values in an array and then loop through it as indicated in How do I split a string on a delimiter in Bash?:
IFS=, read -ra values <<< "$variable"
for v in "${values[#]}"
do
# things with "$v"
done
Test
$ variable="abc,def,ghij"
$ IFS=","
$ for v in $variable
> do
> echo "var is $v"
> done
var is abc
var is def
var is ghij
You can find a broader approach in this solution to How to iterate through a comma-separated list and execute a command for each entry.
Examples on the second approach:
$ IFS=, read -ra vals <<< "abc,def,ghij"
$ printf "%s\n" "${vals[#]}"
abc
def
ghij
$ for v in "${vals[#]}"; do echo "$v --"; done
abc --
def --
ghij --
I think syntactically this is cleaner and also passes shell-check linting
variable=abc,def,ghij
for i in ${variable//,/ }
do
# call your procedure/other scripts here below
echo "$i"
done
#/bin/bash
TESTSTR="abc,def,ghij"
for i in $(echo $TESTSTR | tr ',' '\n')
do
echo $i
done
I prefer to use tr instead of sed, becouse sed have problems with special chars like \r \n in some cases.
other solution is to set IFS to certain separator
Another solution not using IFS and still preserving the spaces:
$ var="a bc,def,ghij"
$ while read line; do echo line="$line"; done < <(echo "$var" | tr ',' '\n')
line=a bc
line=def
line=ghij
Here is an alternative tr based solution that doesn't use echo, expressed as a one-liner.
for v in $(tr ',' '\n' <<< "$var") ; do something_with "$v" ; done
It feels tidier without echo but that is just my personal preference.
The following solution:
doesn't need to mess with IFS
doesn't need helper variables (like i in a for-loop)
should be easily extensible to work for multiple separators (with a bracket expression like [:,] in the patterns)
really splits only on the specified separator(s) and not - like some other solutions presented here on e.g. spaces too.
is POSIX compatible
doesn't suffer from any subtle issues that might arise when bash’s nocasematch is on and a separator that has lower/upper case versions is used in a match like with ${parameter/pattern/string} or case
beware that:
it does however work on the variable itself and pop each element from it - if that is not desired, a helper variable is needed
it assumes var to be set and would fail if it's not and set -u is in effect
while true; do
x="${var%%,*}"
echo $x
#x is not really needed here, one can of course directly use "${var%%:*}"
if [ -z "${var##*,*}" ] && [ -n "${var}" ]; then
var="${var#*,}"
else
break
fi
done
Beware that separators that would be special characters in patterns (e.g. a literal *) would need to be quoted accordingly.
Here's my pure bash solution that doesn't change IFS, and can take in a custom regex delimiter.
loop_custom_delimited() {
local list=$1
local delimiter=$2
local item
if [[ $delimiter != ' ' ]]; then
list=$(echo $list | sed 's/ /'`echo -e "\010"`'/g' | sed -E "s/$delimiter/ /g")
fi
for item in $list; do
item=$(echo $item | sed 's/'`echo -e "\010"`'/ /g')
echo "$item"
done
}
Try this one.
#/bin/bash
testpid="abc,def,ghij"
count=`echo $testpid | grep -o ',' | wc -l` # this is not a good way
count=`expr $count + 1`
while [ $count -gt 0 ] ; do
echo $testpid | cut -d ',' -f $i
count=`expr $count - 1 `
done
I've got a txt file with several lines, each one describing a remote server, like this:
user#server:port:remote_working_path:whether_using_VPN
The : char separates the 4 fields.
I need to operate batch actions within each server, hence I need to parse each line and set appropriate variables. Right now, what I've coded is this:
while read server;
do
echo "$server" | awk -F ':' '{print $1}' &&
echo "$server" | awk -F ':' '{print $2}' &&
echo "$server" | awk -F ':' '{print $3}'
echo "$VPN"
declare $( echo "$server" | awk -F ':' '{print $VPN=$4}' )
echo 'VPN: '$VPN
done < $CUSTOMER_SERVERS_FILE
This script only prints the first 3 fields, and in my intentions should also set $VPN variable as the 4th field. However this seems way broken, and I'm being unable to fix it. How should I modify it so that $VPN = $4?
First, you don't need to use awk in this case. You could try to use something like :
while IFS=':' read -ra array; do
# "${array[0]}" => first field
# "${array[1]}" => second field
# ...
# "${array[#]}" => all fields
done < "$CUSTOMER_SERVERS_FILE"
Then if you want to set VPN variable with the 4th field, you could use :
while IFS=':' read -ra array; do
# ...
VPN="${array[3]}"
done < "$CUSTOMER_SERVERS_FILE"
Another solution :
while IFS=':' read -r address port path vpn trash; do
# The variables $adress $port $path and $vpn are assigned.
# $trash is set with other fields if there are more than 4 fields
done
Finally, when you want to assign the output of a command in a variable, you could do :
var="$(command)"
# or
var="`command`"
I am trying to right a bash script to do multiple checks and searches for a CMS my company uses. I trying to implement a function for a user to be able to search for a certain macro call and the function return all the files that contain the call, the line the macro is called on, and the actual code in the macro call. What I have seems to be getting screwed up by the fact I am using a for loop to format the output. Here's the snippet of the script I am working on:
elif [ "$choice" = "2" ]
then
echo -e "\n What macro call are we looking for $name?"
read macrocall
for i in $(grep -inR "$macrocall" $sitepath/templates/macros/); do
file=$(echo $i | cut -d\: -f1 | awk -F\/ '{ print $NF }')
line=$(echo $i | cut -d\: -f2)
calltext=$(echo $i | cut -d\: -f3-)
echo -e "\nFile: $file"
echo -e "\nLine: $line"
echo -e "\nMacro Call from file: $calltext"
done
fi
the current script runs the first few fields until it gets a a space and then everything gets all screwy. Anybody have any idea how I can have the for loops deliminator to be each result of the grep? any suggestions would be helpful. Let me know if any of you need more info. Thanks!
The right way to do this would be more like:
printf "\n What macro call are we looking for %s?" "$name"
read macrocall
# ensure globbing is off and set IFS to a newline after saving original values
oSET="$-"; set -f; oIFS="$IFS"; IFS=$'\n'
awk -v macrocall="$macrocall" '
BEGIN { lc_macrocall = "\\<" tolower(macrocall) "\\>" }
tolower($0) ~ lc_macrocall {
file=FILENAME
sub(/.*\//,"",file)
printf "\n%s\n", file
printf "\n%d\n", FNR
printf "\nMacro Call from file: %s\n", $0
}
' $(find "$sitepath/templates/macros" -type f -print)
# restore original IFS and globbing values
IFS="$oIFS"; set +f -"$oSET"
This solves the problem of having spaces in your file names as originally requested, but also handles globbing characters in your file names, and the various typical echo issues.
You can set the internal field separator $IFS (which is normally set to space, tab and newline) to just newline to get around this problem:
IFS="\n"
I'm trying to read file line by line in bash.
Every line has format as follows text|number.
I want to produce file with format as follows text,text,text etc. so new file would have just text from previous file separated by comma.
Here is what I've tried and couldn't get it to work :
FILENAME=$1
OLD_IFS=$IFSddd
IFS=$'\n'
i=0
for line in $(cat "$FILENAME"); do
array=(`echo $line | sed -e 's/|/,/g'`)
echo ${array[0]}
i=i+1;
done
IFS=$OLD_IFS
But this prints both text and number but in different format text number
here is sample input :
dsadadq-2321dsad-dasdas|4212
dsadadq-2321dsad-d22as|4322
here is sample output:
dsadadq-2321dsad-dasdas,dsadadq-2321dsad-d22as
What did I do wrong?
Not pure bash, but you could do this in awk:
awk -F'|' 'NR>1{printf(",")} {printf("%s",$1)}'
Alternately, in pure bash and without having to strip the final comma:
#/bin/bash
# You can get your input from somewhere else if you like. Even stdin to the script.
input=$'dsadadq-2321dsad-dasdas|4212\ndsadadq-2321dsad-d22as|4322\n'
# Output should be reset to empty, for safety.
output=""
# Step through our input. (I don't know your column names.)
while IFS='|' read left right; do
# Only add a field if it exists. Salt to taste.
if [[ -n "$left" ]]; then
# Append data to output string
output="${output:+$output,}$left"
fi
done <<< "$input"
echo "$output"
No need for arrays and sed:
while IFS='' read line ; do
echo -n "${line%|*}",
done < "$FILENAME"
You just have to remove the last comma :-)
Using sed:
$ sed ':a;N;$!ba;s/|[0-9]*\n*/,/g;s/,$//' file
dsadadq-2321dsad-dasdas,dsadadq-2321dsad-d22as
Alternatively, here is a bit more readable sed with tr:
$ sed 's/|.*$/,/g' file | tr -d '\n' | sed 's/,$//'
dsadadq-2321dsad-dasdas,dsadadq-2321dsad-d22as
Choroba has the best answer (imho) except that it does not handle blank lines and it adds a trailing comma. Also, mucking with IFS is unnecessary.
This is a modification of his answer that solves those problems:
while read line ; do
if [ -n "$line" ]; then
if [ -n "$afterfirst" ]; then echo -n ,; fi
afterfirst=1
echo -n "${line%|*}"
fi
done < "$FILENAME"
The first if is just to filter out blank lines. The second if and the $afterfirst stuff is just to prevent the extra comma. It echos a comma before every entry except the first one. ${line%|\*} is a bash parameter notation that deletes the end of a paramerter if it matches some expression. line is the paramter, % is the symbol that indicates a trailing pattern should be deleted, and |* is the pattern to delete.