$ cat file.txt
example1#domain1-username
I'd like to parse file.txt and export the contents to variables like:
var1=example1#domain1
var2=username
Using just Bash builtins:
$ IFS=- read var1 var2 <<< "$(< file.txt)"
$ declare -p var1 var2
declare -- var1="example1#domain1"
declare -- var2="username"
This sets the field separator IFS to -, then reads the file into the two variables.
<<< "$(< file.txt)" is a but unwieldy, as we're treating the file just like the single line of text that it is.
var1=$(cut -d "-" -f 1 file.txt)
var2=$(cut -d "-" -f 2 file.txt)
The following command will set var1 and var2 in a single pass over file.txt:
. file.txt
Related
In bash/shell script,
I have a string variable "metaItems" with 2 values
metaItems= src/profiles/API Only.profile src/profiles/Chatter External User.profile
i want to insert comma before every "src/" value and store the values in an array as shown below
for e.g
array= {src/profiles/API Only.profile,src/profiles/Chatter External User.profile}
how to achieve it ?
You actually don't want to insert a ',', but instead you want to insert a '\n' so that you can set IFS (Internal Field Separator) to word-split on the newline and separate your strings into separate elements of an array.
For example:
#!/bin/bash
metaItems="src/profiles/API Only.profile src/profiles/Chatter External User.profile"
oifs="$IFS" # save original IFS
IFS=$'\n' # set IFS to split on '\n'
arr=( $(sed 's|\ src/|\nsrc/|g' <<< $metaItems) )
IFS="$oifs" # restore original IFS
declare -p arr
Example Use/Output
With the above script in splitarray,
$ bash splitarray
declare -a arr=([0]="src/profiles/API Only.profile" [1]="src/profiles/Chatter External User.profile")
Which show your desired strings separated into individual elements of the array arr.
echo "metaItems= src/profiles/API Only.profile src/profiles/Chatter External User.profile" | sed -r -e "s/([^=]) src/\1,src/g" -e "s/metaItems= (.*)/array= {\1}/"
$echo $metaItems
src/profiles/API Only.profile src/profiles/Chatter External User.profile
$IFS=',' read -ra array <<< $(echo $metaItems | sed 's#src\/#,&#g')
$for i in "${array[#]}"; do echo $i; done
src/profiles/API Only.profile
src/profiles/Chatter External User.profile
$
In bash script, how can I read the file line by line and assign to the variable with delimiter?
example.txt file contents:
string1
string2
string3
string4
Expected output:
string1,string2,string3,string4
Thanks in advance
Apparently my answer below leaves a comma at the end of the line. A quick workaround is to use the following builtin in Unix:
paste -sd, example.txt
Where you use the paste program to concatenate all the lines into one and then add the string delimiter ','
Using the builtin commands in unix:
tr '\n' ',' < example.txt
This can be broken down as truncating all Newline widcards and inserting a comma delimiter instead.
Other possible ways, just for fun:
mapfile -t a < example.txt
(IFS=,; echo "${a[*]}")
mapfile -t a < example.txt
foo=$(printf '%s' "${a[#]/%/,}")
echo "${foo%,}"
foo=$(<example.txt)
echo "${foo//$'\n'/,}"
{
IFS= read -r foo
while IFS= read -r line; do
foo+=,$line
done
} < example.txt
echo "$foo"
sed ':a;N;$!ba;s/\n/,/g' example.txt
It should work:
#!/bin/bash
output=''
while IFS='' read -r line || [[ -n "$line" ]]; do
output=$output:",$line"
done < "$1"
echo $output
Give the file as argument
I want to input multiple strings.
For example:
abc
xyz
pqr
and I want output like this (including quotes) in a file:
"abc","xyz","pqr"
I tried the following code, but it doesn't give the expected output.
NextEmail=","
until [ "a$NextEmail" = "a" ];do
echo "Enter next E-mail: "
read NextEmail
Emails="\"$Emails\",\"$NextEmail\""
done
echo -e $Emails
This seems to work:
#!/bin/bash
# via https://stackoverflow.com/questions/1527049/join-elements-of-an-array
function join_by { local IFS="$1"; shift; echo "$*"; }
emails=()
while read line
do
if [[ -z $line ]]; then break; fi
emails+=("$line")
done
join_by ',' "${emails[#]}"
$ bash vvuv.sh
my-email
another-email
third-email
my-email,another-email,third-email
$
With sed and paste:
sed 's/.*/"&"/' infile | paste -sd,
The sed command puts "" around each line; paste does serial pasting (-s) and uses , as the delimiter (-d,).
If input is from standard input (and not a file), you can just remove the input filename (infile) from the command; to store in a file, add a redirection at the end (> outfile).
If you can withstand a trailing comma, then printf can convert an array, with no loop required...
$ readarray -t a < <(printf 'abc\nxyx\npqr\n' )
$ declare -p a
declare -a a=([0]="abc" [1]="xyx" [2]="pqr")
$ printf '"%s",' "${a[#]}"; echo
"abc","xyx","pqr",
(To be fair, there's a loop running inside bash, to step through the array, but it's written in C, not bash. :) )
If you wanted, you could replace the final line with:
$ printf -v s '"%s",' "${a[#]}"
$ s="${s%,}"
$ echo "$s"
"abc","xyx","pqr"
This uses printf -v to store the imploded text into a variable, $s, which you can then strip the trailing comma off using Parameter Expansion.
I have been working in bash, and need to create a string argument. bash is a newish for me, to the point that I dont know how to build a string in bash from a list.
// foo.txt is a list of abs file names.
/foo/bar/a.txt
/foo/bar/b.txt
/delta/test/b.txt
should turn into: a.txt,b.txt,b.txt
OR: /foo/bar/a.txt,/foo/bar/b.txt,/delta/test/b.txt
code
s = ""
for file in $(cat foo.txt);
do
#what goes here? s += $file ?
done
myShellScript --script $s
I figure there was an easy way to do this.
with for loop:
for file in $(cat foo.txt);do echo -n "$file",;done|sed 's/,$/\n/g'
with tr:
cat foo.txt|tr '\n' ','|sed 's/,$/\n/g'
only sed:
sed ':a;N;$!ba;s/\n/,/g' foo.txt
This seems to work:
#!/bin/bash
input="foo.txt"
while IFS= read -r var
do
basename $var >> tmp
done < "$input"
paste -d, -s tmp > result.txt
output: a.txt,b.txt,b.txt
basename gets you the file names you need and paste will put them in the order you seem to need.
The input field separator can be used with set to create split/join functionality:
# split the lines of foo.txt into positional parameters
IFS=$'\n'
set $(< foo.txt)
# join with commas
IFS=,
echo "$*"
For just the file names, add some sed:
IFS=$'\n'; set $(sed 's|.*/||' foo.txt); IFS=,; echo "$*"
I am using Linux and bash.
I have a simple text file like below:
VAR1=100
VAR2=5
VAR3=0
VAR4=99
I want to extract by means of bash the value of VAR2, that is 5.
How could I do that?
Assuming the file is called vars.txt
sed -n 's/^VAR2=\(.*\)/\1/p' < vars.txt
You can use the value elsewhere like this using single back quotes
echo VAR2=`sed -n 's/^VAR2=\(.*\)/\1/p' < txt`
The simplest way might be to use source or simply . to read and execute the file. This would work with your example, because there are no spaces in the variable values. Otherwise you need to use grep + cut or awk, as stated in other answers.
. /path/to/your/file
echo $VAR2
[edit]
As stated by dawg, this would make the other variables available in your script too, and possibly overwrite existing variables.
Given:
$ echo "$txt"
VAR1=100
VAR2=5
VAR3=0
VAR4=99
You can use awk:
$ echo "$txt" | awk -F= '/^VAR2/ { print $2 }'
5
Or grep and cut:
$ echo "$txt" | egrep '^VAR2=\d+' | cut -d = -f 2
5
On Bash, you can insert the value of those assignments into the current shell using source and filter the lines you wish to use. In this case, only the line VAR2=5 will be used. You need to write that to a file and then source that file:
$ echo "$txt" | grep '^VAR2' > tmp && source tmp && rm tmp
$ echo $VAR2
5
For the files as described, you can just source the file as bash script which will run it's content and update you workspace environment with it. For example:
source file.txt
echo $VAR2
Assume this as your txt file, named test.txt
VAR2 = 5
VAR3 = 0
VAR4 = 99
you can cat test.txt | grep 'VAR2' | awk '{printf $3}'
and then your output will be: 5
Here, cat test.txt will display the content of test.txt in your terminal,grep 'VAR2' will list lines containing 'VAR2' and awk '{printf $3}' will print the value of the variable