Here is a LIST:
List = "abcd 1234 jvm something"
How to get the second element "1234" without looping all the list?
Add a comment
|
2 Answers
no spaces between equal sign
$ List="abcd 1234 jvm something"
$ set -- $List
$ echo $2
1234
Some other ways, although not as efficient as using shell's internals
$ echo $List | cut -d" " -f2
1234
$ echo $List | awk '{print $2}'
1234
$ echo $List | sed 's/^.[^ \t]* //;s/ .*//'
1234
$ echo $List | tr " " "\n"|sed -n '2p'
1234
-
1
-
2
-
18@Spawn
set -- $somethingsplits$somethingat the$IFScharacter (by default space) and assigns the split parts to the positional variables$1,$2,... Mar 19, 2010 at 3:44 -
As @BenjaminBannier says in his answer: using set this way may pollute the environment. I.e. by overwriting positional parameters. To suggest it as an answer without explaining what it does is irresponsible.– marklingMay 24, 2023 at 10:34
Just to supplement ghostdog's answer: you could also put $List's elements into an array and access the specific list element from there
List="abcd 1234 jvm something"
arr=($List)
echo ${arr[1]}
Note that the array indices are counted 0,1,2,... .
This has the advantage of not polluting the shell environment with too many new variables.
answered Mar 19, 2010 at 4:03
-
@BenjaminBannier, how can you select multiple elements. Is there some syntax like ${arr[1,2,3]}$ (not this, since I tried, but like this) or do I need to use a for loop.– KvotheApr 4, 2019 at 12:51
-
@Kvothe, you can take a slice from the list and loop over them. E.g.
for v in "${arr[@]:1}"; do echo "$v"; done... (i) takes all array elements"${arr[@]}", (ii) gets a slice of them, consisting of 2nd through last elements"${arr[@]:1}", and (iii) loops each into$v.– marklingMay 24, 2023 at 10:44