CODEWITHSUNDEEP
linuxbashunixarguments
Chloe
Chloe

Reputation: 1

How to create a string=$* without arguments $1 and $2

I have a script that takes in several arguments.

I need everything but $1 and $2 in a string.

I have tried this:

message="$*"
words= $(grep -v "$2"|"$3" $message)

but it doesn't work, it gives me the error:

./backup: line 26: First: command not found

Upvotes: 0

Views: 635

Answers (3)

David Jones
David Jones

Reputation: 5139

Use shift 2 to shift the arguments along (it drops the first n arguments). If you need "$1" and "$2" for later, save them in variables first.

Note that in shell, assignments to variables cannot have whitespace either side of the =.

First=$1
Second=$2
shift 2
Message=$@

Upvotes: 3

Benjamin W.
Benjamin W.

Reputation: 52112

You can use a subarray:

$ set -- arg1 arg2 arg3 arg4
$ str=${*:3}
$ echo "$str"
arg3 arg4

More often than not, it's good practice to preserve the arguments as separate elements, though, which you can do by using $@ and assigning to a new array:

$ arr=("${@:3}")
$ declare -p arr
declare -a arr=([0]="arg3" [1]="arg4")

Notice that in str=${*:3}, quoting isn't necessary, but in arr=("${@:3}"), it is (or the arguments would be split on whitespace).

As for your error message: your command

words= $(grep -v "$2"|"$3" $message)

does the following:

  • It sets a variable words to the empty string for the environment of the command (because there is a blank after =).
  • It tries to set up a pipeline consisting of two commands, grep -v "$2" and "$3" $message. The first of these commands would just hang and wait for input; the second one tries to run the contents of $3 as a command; presumably, based on your error message, $3 contains First.
  • If the pipeline would actually run, its output would be run as a command (again because of the blank to the right of =).

Upvotes: 0

tsekman
tsekman

Reputation: 398

Maybe something like this?

[root@tsekmanrhel771 ~]# cat ./skip1st2.sh
#!/bin/bash

COUNT=0

for ARG in "$@"
do
    COUNT=$[COUNT + 1]

    if [ ${COUNT} -gt 2 ]; then
        RESULT="${RESULT} ${ARG}"
    fi
done

echo ${RESULT}

[root@tsekmanrhel771 ~]# ./skip1st2.sh first second third 4 5 6 7
third 4 5 6 7

Upvotes: 0

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