Okay. I am kind of lost and google search isn't helping me much.
I have a command like:
filesize_filename=$(echo $line | awk ' ''{print $5":"$9}')
echo $filesize_filename
1024:/home/test
Now this one saves the two returns or awk'ed items into one variable. I'd like to achieve something like this:
filesize,filename=$(echo $line | awk ' ''{print $5":"$9}')
So I can access them individually like
echo $filesize
1024
echo $filename
/home/test
How to I achieve this?
Thanks.
Populate a shell array with the awk output and then do whatever you like with it:
$ fileInfo=( $(echo "foo 1024 bar /home/test" | awk '{print $2, $4}') )
$ echo "${fileInfo[0]}"
1024
$ echo "${fileInfo[1]}"
/home/test
If the file name can contain spaces then you'll have to adjust the FS and OFS in awk and the IFS in shell appropriately.
You may not need awk at all of course:
$ line="foo 1024 bar /home/test"
$ fileInfo=( $line )
$ echo "${fileInfo[1]}"
1024
$ echo "${fileInfo[3]}"
/home/test
but beware of globbing chars in $line matching on local file names in that last case. I expect there's a more robust way to populate a shell array from a shell variable but off the top of my head I can't think of it.
Use bash's read for that:
read size name < "$(awk '{print $5, $9}' <<< "$line")"
# Now you can output them separately
echo "$size"
echo "$name"
You can use process substitution on awk's output:
read filesize filename < <(echo "$line" | awk '{print $5,$9}')
You can totally avoid awk by doing:
read _ _ _ _ filesize _ _ _ filename _ <<< "$line"
Related
I have a file with the following content:
"X-Apple-I-MD-M" = "MR7v7ctwW0yr3mAUY3rAluXgOReA4CIn1JWJS2ba1s";
I want to extract the returned results Output as:
MR7v7ctwW0yr3mAUY3rAluXgOReA4CIn1JWJS2ba1s
Tks Everybody!
One awk idea, assuming this is the only line in the file:
$ awk -F'"' '{print $4}' file
MR7v7ctwW0yr3mAUY3rAluXgOReA4CIn1JWJS2ba1s
If there are other lines and you wish to focus only on the line with the string "X-Apple-I-MD-M":
Input file:
$ cat file
some line to ignore
"X-Apple-I-MD-M" = "MR7v7ctwW0yr3mAUY3rAluXgOReA4CIn1JWJS2ba1s";
other line to ignore and "with" some "quotes"
New awk idea:
$ pattern='X-Apple-I-MD-M'
$ awk -v ptn="${pattern}" -F'"' '$2==ptn {print $4}' file
MR7v7ctwW0yr3mAUY3rAluXgOReA4CIn1JWJS2ba1s
And saving the awk result in a variable:
$ mystring=$(awk ... )
$ echo "${mystring}"
MR7v7ctwW0yr3mAUY3rAluXgOReA4CIn1JWJS2ba1s
NOTE: keep in mind if there are multiple matching lines in file then ${mystring} will contain a multi-line value (eg, line1match\nline2match\nline3match
I always like sed.
$: echo '"X-Apple-I-MD-M" = "MR7v7ctwW0yr3mAUY3rAluXgOReA4CIn1JWJS2ba1s";'| sed -E 's/^.*= *"([^"]+)" *; *$/\1/'
MR7v7ctwW0yr3mAUY3rAluXgOReA4CIn1JWJS2ba1s
if it's a file,
$: sed -E 's/^.*= *"([^"]+)" *; *$/\1/' file
MR7v7ctwW0yr3mAUY3rAluXgOReA4CIn1JWJS2ba1s
With GNU grep(1), something like.
grep -Po '(?<="X-Apple-I-MD-M" = ").*(?=";)' <<< '"X-Apple-I-MD-M" = "MR7v7ctwW0yr3mAUY3rAluXgOReA4CIn1JWJS2ba1s";'
If it is in a file.
grep -Po '(?<="X-Apple-I-MD-M" = ").*(?=";)' file.txt
If your content is consistent, an ugly solution is:
VAL='"X-Apple-I-MD-M" = "MR7v7ctwW0yr3mAUY3rAluXgOReA4CIn1JWJS2ba1s";'
echo $VAL
echo $VAL | awk '{split($0, a, " = "); print(substr(a[2], 2, length(a[2]) - 3))}'
Guessing by the bash tag, this is probably supposed to be in pure Bash, without external processes…? Two (somewhat) random options:
while IFS='"' read _ _ _ code _; do
echo "$code"
done
while read line; do
line="${line#\"*\" = \"}"
line="${line%\";}"
echo "$line"
done
I have a TSV file with 3 columns, that is assigned to paramfile.
Here is my script:
#! /bin/bash -l
paramfile=/path/to/file
while
sample=`sed -n ${number}p $paramfile | awk '{print $1}'`
Reads1=`sed -n ${number}p $paramfile | awk '{print $2}'`
Reads2=`sed -n ${number}p $paramfile | awk '{print $3}'`
do
./program.sh $sample $reads1 $reads2
done
I want it to read the TSV line by line, and for each line take the content of each column and insert it into my program, to be used as an option in program.sh
I know I haven't got the loop qutie right, what am I missing?
read with a ‘custom’ $IFS can read TSV* into variables, e.g:
#!/bin/bash
paramfile=/path/to/file
while IFS="$(printf '\t')" read -r sample reads1 reads2 _
do
./program.sh "${sample}" "${reads1}" "${reads2}"
done < "${paramfile}"
The _ is for dropping any trailing cells.
And I took the liberty to quote all variables, as one should.
*Not quoted TSV, though.
I need to read a file that has lines like
user=username1
pass=password1
How can I read multiple lines like this into separate variables like username and password?
Would I use awk or grep? I have found ways to read lines into variables with grep but would I need to read the file for each individual item?
The end result is to use these variables to access a database via the command line. So I need to be able to read, store and use these values in other commands.
if the process which generates the file is safe and has shell syntax just source the file.
. ./file
Otherwise the file can be processes before to add quotes
perl -ne 'if (/^([A-Za-z_]\w*)=(.*)/) {$k=$1;$v=$2;$v=~s/\x27/\x27\\\x27\x27/g;print "$k=\x27$v\x27\n";}' <file >file2
. ./file2
If you want to use awk then
Input
$ cat file
user=username1
pass=password1
Reading
$ user=$(awk -F= '$1=="user"{print $2;exit}' file)
$ pass=$(awk -F= '$1=="pass"{print $2;exit}' file)
Output
$ echo $user
username1
$ echo $pass
password1
You could use a loop for your file perhaps, but this is probably the functionality you're looking for.
$ echo 'user=username1' | awk -F= '{print $2}'
username1
Using the -F flag sets the delimiter to = and we select the 2nd item from the row.
file.txt:
user=username1
pass=password1
user=username2
pass=password2
user=username3
pass=password3
Do to avoid browsing several times the file file.txt:
#!/usr/bin/env bash
func () {
echo "user:$1 pass:$2"
}
i=0
while IFS='' read -r line; do
if [ $i -eq 0 ]; then
i=1
user=$(echo ${line} | cut -f2 -d'=')
else
i=0
pass=$(echo ${line} | cut -f2 -d'=')
func "$user" "$pass"
fi
done < file.txt
Output:
user:username1 pass:password1
user:username2 pass:password2
user:username3 pass:password3
I'm trying to cut the below string starting on the single quote:
name1=O'Reilly
so it leaves:
name2=Reilly
That's easy from the command line with the following commands:
echo $name | cut -d\' -f
echo $name | awk -F\' '{print $2}'
However when I run these commands from a script the string remains unaltered. I've been looking into problems with using single quotes as a delimiter but couldn't find anything. Any way to solve this issue?
That does not change the string the variable expands to, it just outputs the result of string manipulation.
If you want to create a new reference for variable name, use command substitution to save the result of cut/awk operation as variable name:
% name="O'Reilly"
% echo "$name" | awk -F\' '{print $2}'
Reilly
% name=$(echo "$name" | awk -F\' '{print $2}')
% echo "$name"
Reilly
On the other hand, if you want to declare the input as one (name1), and save the output as a different variable (name2):
% name1="O'Reilly"
% name2=$(echo "$name1" | awk -F\' '{print $2}')
% echo "$name2"
Reilly
This might be easier to get using Parameter expansion though:
$ name="O'Reilly"
$ echo "${name#*\'}"
Reilly
$ name="${name#*\'}"
$ echo "$name"
Reilly
This might be a very basic question but I was not able to find solution. I have a script:
If I run w | awk '{print $1}' in command line in my server I get:
f931
smk591
sc271
bx972
gaw844
mbihk988
laid640
smk59
ycc951
Now I need to use this list in my bash script one by one and manipulate some operation on them. I need to check their group and print those are in specific group. The command to check their group is id username. How can I save them or iterate through them one by one in a loop.
what I have so far is
tmp=$(w | awk '{print $1})
But it only return first record! Appreciate any help.
Populate an array with the output of the command:
$ tmp=( $(printf "a\nb\nc\n") )
$ echo "${tmp[0]}"
a
$ echo "${tmp[1]}"
b
$ echo "${tmp[2]}"
c
Replace the printf with your command (i.e. tmp=( $(w | awk '{print $1}') )) and man bash for how to work with bash arrays.
For a lengthier, more robust and complete example:
$ cat ./tstarrays.sh
# saving multi-line awk output in a bash array, one element per line
# See http://www.thegeekstuff.com/2010/06/bash-array-tutorial/ for
# more operations you can perform on an array and its elements.
oSET="$-"; set -f # save original set flags and turn off globbing
oIFS="$IFS"; IFS=$'\n' # save original IFS and make IFS a newline
array=( $(
awk 'BEGIN{
print "the quick brown"
print " fox jumped\tover\tthe"
print "lazy dogs back "
}'
) )
IFS="$oIFS" # restore original IFS value
set +f -$oSET # restore original set flags
for (( i=0; i < ${#array[#]}; i++ ));
do
printf "array[%d] of length=%d: \"%s\"\n" "$i" "${#array[$i]}" "${array[$i]}"
done
printf -- "----------\n"
printf -- "array[#]=\n\"%s\"\n" "${array[#]}"
printf -- "----------\n"
printf -- "array[*]=\n\"%s\"\n" "${array[*]}"
.
$ ./tstarrays.sh
array[0] of length=22: "the quick brown"
array[1] of length=23: " fox jumped over the"
array[2] of length=21: "lazy dogs back "
----------
array[#]=
"the quick brown"
array[#]=
" fox jumped over the"
array[#]=
"lazy dogs back "
----------
array[*]=
"the quick brown fox jumped over the lazy dogs back "
A couple of non-obvious key points to make sure your array gets populated with exactly what your command outputs:
If your command output can contain globbing characters than you should disable globbing before the command (oSET="$-"; set -f) and re-enable it afterwards (set +f -$oSET).
If your command output can contain spaces then set IFS to a newline before the command (oIFS="$IFS"; IFS=$'\n') and set it back to it's old value after the command (IFS="$oIFS").
tmp=$(w | awk '{print $1}')
while read i
do
echo "$i"
done <<< "$tmp"
You can use a for loop, i.e.
for user in $(w | awk '{print $1}'); do echo $user; done
which in a script would look nicer as:
for user in $(w | awk '{print $1}')
do
echo $user
done
You can use the xargs command to do this:
w | awk '{print $1}' | xargs -I '{}' id '{}'
With the -I switch, xargs will take each line of its standard input separately, then construct and execute a command line by replacing the specified string '{}' in the command line template with the input line
I guess you should use who instead of w. Try this out,
who | awk '{print $1}' | xargs -n 1 id