this is probably a very simple question. I looked at other answers but couldn't come up with a solution. I have a 365 line date file. file as below,
01-01-2000
02-01-2000
I need to read this file line by line and assign each day to a separate variable. like this,
d001=01-01-2000
d002=02-01-2000
I tried while read commands but couldn't get them to work.It takes a lot of time to shoot one by one. How can I do it quickly?
Trying to create named variable out of an associative array, is time waste and not supported de-facto. Better use this, using an associative array:
#!/bin/bash
declare -A array
while read -r line; do
printf -v key 'd%03d' $((++c))
array[$key]=$line
done < file
Output
for i in "${!array[#]}"; do echo "key=$i value=${array[$i]}"; done
key=d001 value=01-01-2000
key=d002 value=02-01-2000
Assumptions:
an array is acceptable
array index should start with 1
Sample input:
$ cat sample.dat
01-01-2000
02-01-2000
03-01-2000
04-01-2000
05-01-2000
One bash/mapfile option:
unset d # make sure variable is not currently in use
mapfile -t -O1 d < sample.dat # load each line from file into separate array location
This generates:
$ typeset -p d
declare -a d=([1]="01-01-2000" [2]="02-01-2000" [3]="03-01-2000" [4]="04-01-2000" [5]="05-01-2000")
$ for i in "${!d[#]}"; do echo "d[$i] = ${d[i]}"; done
d[1] = 01-01-2000
d[2] = 02-01-2000
d[3] = 03-01-2000
d[4] = 04-01-2000
d[5] = 05-01-2000
In OP's code, references to $d001 now become ${d[1]}.
A quick one-liner would be:
eval $(awk 'BEGIN{cnt=0}{printf "d%3.3d=\"%s\"\n",cnt,$0; cnt++}' your_file)
eval makes the shell variables known inside your script or shell. Use echo $d000 to show the first one of the newly defined variables. There should be no shell special characters (like * and $) inside your_file. Remove eval $() to see the result of the awk command. The \" quoted %s is to allow spaces in the variable values. If you don't have any spaces in your_file you can remove the \" before and after %s.
Related
I have done some processing in perl, and got the result in perl's hash data structure. Usually in bash, when I try to retrieve result from other script like
output=$(perl -E '...')
I got the output in string. Is it possible to save the result in bash array?
Assuming a perl variable hash is an associative array, please try:
declare -A "output=($(perl -e '
$hash{"foo"} = "xx"; # just an example
$hash{"bar"} = "yy"; # ditto
for (keys %hash) {print "[\"$_\"]=\"$hash{$_}\"\n"}'))"
for i in "${!output[#]}"; do
echo "$i => ${output[$i]}" # see the result
done
The outermost double quotes around output=.. is required to tell declare
to evaluate the argument.
[Update]
Considering tripleee's comment, here is a robust version against special characters:
mapfile -d "" -t a < <(perl -e '
$hash{"baz"} = "boo"; # example
$hash{"foo"} = "x\"x"; # example with a double quote
$hash{"bar"} = "y\ny"; # example with a newline
print join("\0", %hash), "\0"') # use a nul byte as a delimiter
declare -A output # bash associative array
for ((i = 0; i < ${#a[#]}; i+=2 )); do
output[${a[i]}]=${a[i+1]} # key and value pair
done
for i in "${!output[#]}"; do
echo "$i => ${output[$i]}" # see the result
done
The conversion from perl variables to bash variables works only if they are free of null bytes (\n), as perl can store null bytes in strings, but bash cannot.
At least, we can use that limitation to print the hash in perl with null delimiters and safely parse it in bash again:
declare -A "array=($(
perl -e 'print join("\0", %hash), "\0"' |
xargs -0 printf '[%q]=%q '
))"
Please note that neither %q nor -0 are specified by posix. For a more portable solution see tshiono's answer.
If the hash is very big such that ARG_MAX might be exceeded you should ensure that xargs does not split a key value pair across two calls to printf. To do so, add the option -n2 (or any other number 2n where you are sure that n key value pairs never exceed ARG_MAX).
I have a variable equal to a string, which is a series of key/value pairs separated by newlines.
I want to then replace these newline characters with spaces, and set a new variable equal to the result
From various answers on the internet I've arrived at the following:
#test.txt has the content:
#test=example
#what=s0omething
vars="$(cat ./test.txt)"
formattedVars= $("$vars" | tr '\n' ' ')
echo "$taliskerEnvVars"
Problem is when I try to set formattedVars it tries to execute the second line:
script.sh: line 7: test=example
what=s0omething: command not found
I just want formattedVars to equal test=example what=s0omething
What trick am I missing?
Change your line to:
formattedVars=$(tr '\n' ' ' <<< "$secretsContent")
Notice the space of = in your code, which is not permitted in assignment statements.
I see that you are not setting secretsContent in your code, you are setting vars instead.
If possible, use an array to hold contents of the file:
readarray -t vars < ./test.txt # bash 4
or
# bash 3.x
declare -a vars
while IFS= read -r line; do
vars+=( "$line" )
done < ./test.txt
Then you can do what you need with the array. You can make your space-separated list with
formattedVars="${vars[*]}"
, but consider whether you need to. If the goal is to use them as a pre-command modifier, use, for instance,
"${vars[#]}" my_command arg1 arg2
I'm wondering if anyone can help. I've not managed to find much in the way of examples and I'm not sure where to start coding wise either.
I have a file with the following contents...
VarA=/path/to/a
VarB=/path/to/b
VarC=/path/to/c
VarD=description of program
...
The columns are delimited by the '=' and some of the items in the 2nd column may contain gaps as they aren't just paths.
Ideally I'd love to open this in my script once and store the first column as the variable and the second as the value, for example...
echo $VarA
...
/path/to/a
echo $VarB
...
/path/to/a
Is this possible or am I living in a fairy land?
Thanks
You might be able to use the following loop:
while IFS== read -r name value; do
declare "$name=$value"
done < file.txt
Note, though, that a line like foo="3 5" would include the quotes in the value of the variable foo.
A minus sign or a special character isn't allowed in a variable name in Unix.
You may consider using BASH associative array for storing key and value together:
# declare an associative array
declare -A arr
# read file and populate the associative array
while IFS== read -r k v; do
arr["$k"]="$v"
done < file
# check output of our array
declare -p arr
declare -A arr='([VarA]="/path/to/a" [VarC]="/path/to/c" [VarB]="/path/to/b" [VarD]="description of program" )'
What about source my-file? It won't work with spaces though, but will work for what you've shared. This is an example:
reut#reut-home:~$ cat src
test=123
test2=abc/def
reut#reut-home:~$ echo $test $test2
reut#reut-home:~$ source src
reut#reut-home:~$ echo $test $test2
123 abc/def
I am planning a script to manage some pieces of my Linux systems and am at the point of deciding if I want to use bash or python.
I would prefer to do this as a Bash script simply because the commands are easier, but the real deciding factor is configuration. I need to be able to store a multi-dimensional array in the configuration file to tell the script what to do with itself. Storing simple key=value pairs in config files is easy enough with bash, but the only way I can think of to do a multi-dimensional array is a two layer parsing engine, something like
array=&d1|v1;v2;v3&d2|v1;v2;v3
but the marshall/unmarshall code could get to be a bear and its far from user friendly for the next poor sap that has to administer this. If i can't do this easily in bash i will simply write the configs to an xml file and write the script in python.
Is there an easy way to do this in bash?
thanks everyone.
Bash does not support multidimensional arrays, nor hashes, and it seems that you want a hash that values are arrays. This solution is not very beautiful, a solution with an xml file should be better :
array=('d1=(v1 v2 v3)' 'd2=(v1 v2 v3)')
for elt in "${array[#]}";do eval $elt;done
echo "d1 ${#d1[#]} ${d1[#]}"
echo "d2 ${#d2[#]} ${d2[#]}"
EDIT: this answer is quite old, since since bash 4 supports hash tables, see also this answer for a solution without eval.
Bash doesn't have multi-dimensional array. But you can simulate a somewhat similar effect with associative arrays. The following is an example of associative array pretending to be used as multi-dimensional array:
declare -A arr
arr[0,0]=0
arr[0,1]=1
arr[1,0]=2
arr[1,1]=3
echo "${arr[0,0]} ${arr[0,1]}" # will print 0 1
If you don't declare the array as associative (with -A), the above won't work. For example, if you omit the declare -A arr line, the echo will print 2 3 instead of 0 1, because 0,0, 1,0 and such will be taken as arithmetic expression and evaluated to 0 (the value to the right of the comma operator).
This works thanks to 1. "indirect expansion" with ! which adds one layer of indirection, and 2. "substring expansion" which behaves differently with arrays and can be used to "slice" them as described https://stackoverflow.com/a/1336245/317623
# Define each array and then add it to the main one
SUB_0=("name0" "value 0")
SUB_1=("name1" "value;1")
MAIN_ARRAY=(
SUB_0[#]
SUB_1[#]
)
# Loop and print it. Using offset and length to extract values
COUNT=${#MAIN_ARRAY[#]}
for ((i=0; i<$COUNT; i++))
do
NAME=${!MAIN_ARRAY[i]:0:1}
VALUE=${!MAIN_ARRAY[i]:1:1}
echo "NAME ${NAME}"
echo "VALUE ${VALUE}"
done
It's based off of this answer here
If you want to use a bash script and keep it easy to read recommend putting the data in structured JSON, and then use lightweight tool jq in your bash command to iterate through the array. For example with the following dataset:
[
{"specialId":"123",
"specialName":"First"},
{"specialId":"456",
"specialName":"Second"},
{"specialId":"789",
"specialName":"Third"}
]
You can iterate through this data with a bash script and jq like this:
function loopOverArray(){
jq -c '.[]' testing.json | while read i; do
# Do stuff here
echo "$i"
done
}
loopOverArray
Outputs:
{"specialId":"123","specialName":"First"}
{"specialId":"456","specialName":"Second"}
{"specialId":"789","specialName":"Third"}
Independent of the shell being used (sh, ksh, bash, ...) the following approach works pretty well for n-dimensional arrays (the sample covers a 2-dimensional array).
In the sample the line-separator (1st dimension) is the space character. For introducing a field separator (2nd dimension) the standard unix tool tr is used. Additional separators for additional dimensions can be used in the same way.
Of course the performance of this approach is not very well, but if performance is not a criteria this approach is quite generic and can solve many problems:
array2d="1.1:1.2:1.3 2.1:2.2 3.1:3.2:3.3:3.4"
function process2ndDimension {
for dimension2 in $*
do
echo -n $dimension2 " "
done
echo
}
function process1stDimension {
for dimension1 in $array2d
do
process2ndDimension `echo $dimension1 | tr : " "`
done
}
process1stDimension
The output of that sample looks like this:
1.1 1.2 1.3
2.1 2.2
3.1 3.2 3.3 3.4
After a lot of trial and error i actually find the best, clearest and easiest multidimensional array on bash is to use a regular var. Yep.
Advantages: You don't have to loop through a big array, you can just echo "$var" and use grep/awk/sed. It's easy and clear and you can have as many columns as you like.
Example:
$ var=$(echo -e 'kris hansen oslo\nthomas jonson peru\nbibi abu johnsonville\njohnny lipp peru')
$ echo "$var"
kris hansen oslo
thomas johnson peru
bibi abu johnsonville
johnny lipp peru
If you want to find everyone in peru
$ echo "$var" | grep peru
thomas johnson peru
johnny lipp peru
Only grep(sed) in the third field
$ echo "$var" | sed -n -E '/(.+) (.+) peru/p'
thomas johnson peru
johnny lipp peru
If you only want x field
$ echo "$var" | awk '{print $2}'
hansen
johnson
abu
johnny
Everyone in peru that's called thomas and just return his lastname
$ echo "$var" |grep peru|grep thomas|awk '{print $2}'
johnson
Any query you can think of... supereasy.
To change an item:
$ var=$(echo "$var"|sed "s/thomas/pete/")
To delete a row that contains "x"
$ var=$(echo "$var"|sed "/thomas/d")
To change another field in the same row based on a value from another item
$ var=$(echo "$var"|sed -E "s/(thomas) (.+) (.+)/\1 test \3/")
$ echo "$var"
kris hansen oslo
thomas test peru
bibi abu johnsonville
johnny lipp peru
Of course looping works too if you want to do that
$ for i in "$var"; do echo "$i"; done
kris hansen oslo
thomas jonson peru
bibi abu johnsonville
johnny lipp peru
The only gotcha iv'e found with this is that you must always quote the
var(in the example; both var and i) or things will look like this
$ for i in "$var"; do echo $i; done
kris hansen oslo thomas jonson peru bibi abu johnsonville johnny lipp peru
and someone will undoubtedly say it won't work if you have spaces in your input, however that can be fixed by using another delimeter in your input, eg(using an utf8 char now to emphasize that you can choose something your input won't contain, but you can choose whatever ofc):
$ var=$(echo -e 'field one☥field two hello☥field three yes moin\nfield 1☥field 2☥field 3 dsdds aq')
$ for i in "$var"; do echo "$i"; done
field one☥field two hello☥field three yes moin
field 1☥field 2☥field 3 dsdds aq
$ echo "$var" | awk -F '☥' '{print $3}'
field three yes moin
field 3 dsdds aq
$ var=$(echo "$var"|sed -E "s/(field one)☥(.+)☥(.+)/\1☥test☥\3/")
$ echo "$var"
field one☥test☥field three yes moin
field 1☥field 2☥field 3 dsdds aq
If you want to store newlines in your input, you could convert the newline to something else before input and convert it back again on output(or don't use bash...). Enjoy!
I am posting the following because it is a very simple and clear way to mimic (at least to some extent) the behavior of a two-dimensional array in Bash. It uses a here-file (see the Bash manual) and read (a Bash builtin command):
## Store the "two-dimensional data" in a file ($$ is just the process ID of the shell, to make sure the filename is unique)
cat > physicists.$$ <<EOF
Wolfgang Pauli 1900
Werner Heisenberg 1901
Albert Einstein 1879
Niels Bohr 1885
EOF
nbPhysicists=$(wc -l physicists.$$ | cut -sf 1 -d ' ') # Number of lines of the here-file specifying the physicists.
## Extract the needed data
declare -a person # Create an indexed array (necessary for the read command).
while read -ra person; do
firstName=${person[0]}
familyName=${person[1]}
birthYear=${person[2]}
echo "Physicist ${firstName} ${familyName} was born in ${birthYear}"
# Do whatever you need with data
done < physicists.$$
## Remove the temporary file
rm physicists.$$
Output:
Physicist Wolfgang Pauli was born in 1900 Physicist Werner Heisenberg was born in 1901 Physicist Albert Einstein was born in 1879 Physicist Niels Bohr was born in 1885
The way it works:
The lines in the temporary file created play the role of one-dimensional vectors, where the blank spaces (or whatever separation character you choose; see the description of the read command in the Bash manual) separate the elements of these vectors.
Then, using the read command with its -a option, we loop over each line of the file (until we reach end of file). For each line, we can assign the desired fields (= words) to an array, which we declared just before the loop. The -r option to the read command prevents backslashes from acting as escape characters, in case we typed backslashes in the here-document physicists.$$.
In conclusion a file is created as a 2D-array, and its elements are extracted using a loop over each line, and using the ability of the read command to assign words to the elements of an (indexed) array.
Slight improvement:
In the above code, the file physicists.$$ is given as input to the while loop, so that it is in fact passed to the read command. However, I found that this causes problems when I have another command asking for input inside the while loop. For example, the select command waits for standard input, and if placed inside the while loop, it will take input from physicists.$$, instead of prompting in the command-line for user input.
To correct this, I use the -u option of read, which allows to read from a file descriptor. We only have to create a file descriptor (with the exec command) corresponding to physicists.$$ and to give it to the -u option of read, as in the following code:
## Store the "two-dimensional data" in a file ($$ is just the process ID of the shell, to make sure the filename is unique)
cat > physicists.$$ <<EOF
Wolfgang Pauli 1900
Werner Heisenberg 1901
Albert Einstein 1879
Niels Bohr 1885
EOF
nbPhysicists=$(wc -l physicists.$$ | cut -sf 1 -d ' ') # Number of lines of the here-file specifying the physicists.
exec {id_file}<./physicists.$$ # Create a file descriptor stored in 'id_file'.
## Extract the needed data
declare -a person # Create an indexed array (necessary for the read command).
while read -ra person -u "${id_file}"; do
firstName=${person[0]}
familyName=${person[1]}
birthYear=${person[2]}
echo "Physicist ${firstName} ${familyName} was born in ${birthYear}"
# Do whatever you need with data
done
## Close the file descriptor
exec {id_file}<&-
## Remove the temporary file
rm physicists.$$
Notice that the file descriptor is closed at the end.
Bash does not supports multidimensional array, but we can implement using Associate array. Here the indexes are the key to retrieve the value. Associate array is available in bash version 4.
#!/bin/bash
declare -A arr2d
rows=3
columns=2
for ((i=0;i<rows;i++)) do
for ((j=0;j<columns;j++)) do
arr2d[$i,$j]=$i
done
done
for ((i=0;i<rows;i++)) do
for ((j=0;j<columns;j++)) do
echo ${arr2d[$i,$j]}
done
done
Expanding on Paul's answer - here's my version of working with associative sub-arrays in bash:
declare -A SUB_1=(["name1key"]="name1val" ["name2key"]="name2val")
declare -A SUB_2=(["name3key"]="name3val" ["name4key"]="name4val")
STRING_1="string1val"
STRING_2="string2val"
MAIN_ARRAY=(
"${SUB_1[*]}"
"${SUB_2[*]}"
"${STRING_1}"
"${STRING_2}"
)
echo "COUNT: " ${#MAIN_ARRAY[#]}
for key in ${!MAIN_ARRAY[#]}; do
IFS=' ' read -a val <<< ${MAIN_ARRAY[$key]}
echo "VALUE: " ${val[#]}
if [[ ${#val[#]} -gt 1 ]]; then
for subkey in ${!val[#]}; do
subval=${val[$subkey]}
echo "SUBVALUE: " ${subval}
done
fi
done
It works with mixed values in the main array - strings/arrays/assoc. arrays
The key here is to wrap the subarrays in single quotes and use * instead of # when storing a subarray inside the main array so it would get stored as a single, space separated string: "${SUB_1[*]}"
Then it makes it easy to parse an array out of that when looping through values with IFS=' ' read -a val <<< ${MAIN_ARRAY[$key]}
The code above outputs:
COUNT: 4
VALUE: name1val name2val
SUBVALUE: name1val
SUBVALUE: name2val
VALUE: name4val name3val
SUBVALUE: name4val
SUBVALUE: name3val
VALUE: string1val
VALUE: string2val
Lots of answers found here for creating multidimensional arrays in bash.
And without exception, all are obtuse and difficult to use.
If MD arrays are a required criteria, it is time to make a decision:
Use a language that supports MD arrays
My preference is Perl. Most would probably choose Python.
Either works.
Store the data elsewhere
JSON and jq have already been suggested. XML has also been suggested, though for your use JSON and jq would likely be simpler.
It would seem though that Bash may not be the best choice for what you need to do.
Sometimes the correct question is not "How do I do X in tool Y?", but rather "Which tool would be best to do X?"
I do this using associative arrays since bash 4 and setting IFS to a value that can be defined manually.
The purpose of this approach is to have arrays as values of associative array keys.
In order to set IFS back to default just unset it.
unset IFS
This is an example:
#!/bin/bash
set -euo pipefail
# used as value in asscciative array
test=(
"x3:x4:x5"
)
# associative array
declare -A wow=(
["1"]=$test
["2"]=$test
)
echo "default IFS"
for w in ${wow[#]}; do
echo " $w"
done
IFS=:
echo "IFS=:"
for w in ${wow[#]}; do
for t in $w; do
echo " $t"
done
done
echo -e "\n or\n"
for w in ${!wow[#]}
do
echo " $w"
for t in ${wow[$w]}
do
echo " $t"
done
done
unset IFS
unset w
unset t
unset wow
unset test
The output of the script below is:
default IFS
x3:x4:x5
x3:x4:x5
IFS=:
x3
x4
x5
x3
x4
x5
or
1
x3
x4
x5
2
x3
x4
x5
I've got a pretty simple yet smart workaround:
Just define the array with variables in its name. For example:
for (( i=0 ; i<$(($maxvalue + 1)) ; i++ ))
do
for (( j=0 ; j<$(($maxargument + 1)) ; j++ ))
do
declare -a array$i[$j]=((Your rule))
done
done
Don't know whether this helps since it's not exactly what you asked for, but it works for me. (The same could be achieved just with variables without the array)
echo "Enter no of terms"
read count
for i in $(seq 1 $count)
do
t=` expr $i - 1 `
for j in $(seq $t -1 0)
do
echo -n " "
done
j=` expr $count + 1 `
x=` expr $j - $i `
for k in $(seq 1 $x)
do
echo -n "* "
done
echo ""
done
I've got a script 'myscript' that outputs the following:
abc
def
ghi
in another script, I call:
declare RESULT=$(./myscript)
and $RESULT gets the value
abc def ghi
Is there a way to store the result either with the newlines, or with '\n' character so I can output it with 'echo -e'?
Actually, RESULT contains what you want — to demonstrate:
echo "$RESULT"
What you show is what you get from:
echo $RESULT
As noted in the comments, the difference is that (1) the double-quoted version of the variable (echo "$RESULT") preserves internal spacing of the value exactly as it is represented in the variable — newlines, tabs, multiple blanks and all — whereas (2) the unquoted version (echo $RESULT) replaces each sequence of one or more blanks, tabs and newlines with a single space. Thus (1) preserves the shape of the input variable, whereas (2) creates a potentially very long single line of output with 'words' separated by single spaces (where a 'word' is a sequence of non-whitespace characters; there needn't be any alphanumerics in any of the words).
Another pitfall with this is that command substitution — $() — strips trailing newlines. Probably not always important, but if you really want to preserve exactly what was output, you'll have to use another line and some quoting:
RESULTX="$(./myscript; echo x)"
RESULT="${RESULTX%x}"
This is especially important if you want to handle all possible filenames (to avoid undefined behavior like operating on the wrong file).
In case that you're interested in specific lines, use a result-array:
declare RESULT=($(./myscript)) # (..) = array
echo "First line: ${RESULT[0]}"
echo "Second line: ${RESULT[1]}"
echo "N-th line: ${RESULT[N]}"
In addition to the answer given by #l0b0 I just had the situation where I needed to both keep any trailing newlines output by the script and check the script's return code.
And the problem with l0b0's answer is that the 'echo x' was resetting $? back to zero... so I managed to come up with this very cunning solution:
RESULTX="$(./myscript; echo x$?)"
RETURNCODE=${RESULTX##*x}
RESULT="${RESULTX%x*}"
Parsing multiple output
Introduction
So your myscript output 3 lines, could look like:
myscript() { echo $'abc\ndef\nghi'; }
or
myscript() { local i; for i in abc def ghi ;do echo $i; done ;}
Ok this is a function, not a script (no need of path ./), but output is same
myscript
abc
def
ghi
Considering result code
To check for result code, test function will become:
myscript() { local i;for i in abc def ghi ;do echo $i;done;return $((RANDOM%128));}
1. Storing multiple output in one single variable, showing newlines
Your operation is correct:
RESULT=$(myscript)
About result code, you could add:
RCODE=$?
even in same line:
RESULT=$(myscript) RCODE=$?
Then
echo $RESULT $RCODE
abc def ghi 66
echo "$RESULT"
abc
def
ghi
echo ${RESULT#Q}
$'abc\ndef\nghi'
printf '%q\n' "$RESULT"
$'abc\ndef\nghi'
but for showing variable definition, use declare -p:
declare -p RESULT RCODE
declare -- RESULT="abc
def
ghi"
declare -- RCODE="66"
2. Parsing multiple output in array, using mapfile
Storing answer into myvar variable:
mapfile -t myvar < <(myscript)
echo ${myvar[2]}
ghi
Showing $myvar:
declare -p myvar
declare -a myvar=([0]="abc" [1]="def" [2]="ghi")
Considering result code
In case you have to check for result code, you could:
RESULT=$(myscript) RCODE=$?
mapfile -t myvar <<<"$RESULT"
declare -p myvar RCODE
declare -a myvar=([0]="abc" [1]="def" [2]="ghi")
declare -- RCODE="40"
3. Parsing multiple output by consecutives read in command group
{ read firstline; read secondline; read thirdline;} < <(myscript)
echo $secondline
def
Showing variables:
declare -p firstline secondline thirdline
declare -- firstline="abc"
declare -- secondline="def"
declare -- thirdline="ghi"
I often use:
{ read foo;read foo total use free foo ;} < <(df -k /)
Then
declare -p use free total
declare -- use="843476"
declare -- free="582128"
declare -- total="1515376"
Considering result code
Same prepended step:
RESULT=$(myscript) RCODE=$?
{ read firstline; read secondline; read thirdline;} <<<"$RESULT"
declare -p firstline secondline thirdline RCODE
declare -- firstline="abc"
declare -- secondline="def"
declare -- thirdline="ghi"
declare -- RCODE="50"
After trying most of the solutions here, the easiest thing I found was the obvious - using a temp file. I'm not sure what you want to do with your multiple line output, but you can then deal with it line by line using read. About the only thing you can't really do is easily stick it all in the same variable, but for most practical purposes this is way easier to deal with.
./myscript.sh > /tmp/foo
while read line ; do
echo 'whatever you want to do with $line'
done < /tmp/foo
Quick hack to make it do the requested action:
result=""
./myscript.sh > /tmp/foo
while read line ; do
result="$result$line\n"
done < /tmp/foo
echo -e $result
Note this adds an extra line. If you work on it you can code around it, I'm just too lazy.
EDIT: While this case works perfectly well, people reading this should be aware that you can easily squash your stdin inside the while loop, thus giving you a script that will run one line, clear stdin, and exit. Like ssh will do that I think? I just saw it recently, other code examples here: https://unix.stackexchange.com/questions/24260/reading-lines-from-a-file-with-bash-for-vs-while
One more time! This time with a different filehandle (stdin, stdout, stderr are 0-2, so we can use &3 or higher in bash).
result=""
./test>/tmp/foo
while read line <&3; do
result="$result$line\n"
done 3</tmp/foo
echo -e $result
you can also use mktemp, but this is just a quick code example. Usage for mktemp looks like:
filenamevar=`mktemp /tmp/tempXXXXXX`
./test > $filenamevar
Then use $filenamevar like you would the actual name of a file. Probably doesn't need to be explained here but someone complained in the comments.
How about this, it will read each line to a variable and that can be used subsequently !
say myscript output is redirected to a file called myscript_output
awk '{while ( (getline var < "myscript_output") >0){print var;} close ("myscript_output");}'