.profile function duplicates my argument in a string concat?

Question

I use Git commit issue numbers in alignment with GitHub issues. To save time I wrote a bash function to creating a commit message like this:

git commit -m "#4 my commit message"

when calling

gci 4 "my commit message"

where 4 is the issue number, and the commit message follows.

However, my current implementation:

alias gcm='git commit -m '
gci(){
    index="${@:1}"
    message="#$index ${@:2}"
    gcm "$message"
}

yields the commit message twice:

$ gci 4 "my commit message"
[iss2 79d9540] #4 my commit message my commit message
 1 file changed, 0 insertions(+), 0 deletions(-)
 create mode 100644 h.z

What is causing the message to repeat twice?

Answer 1

The ${@:1} and ${@:2} does not work as you expect, use $1 for first parameter and $2 for the second:

alias gcm='git commit -m '
gci(){
    index="$1"
    message="#$index $2"
    gcm "$message"
}

As a side note, alias will not work in noninteractive shells.
No as to ${@:1}, from here:

${var:pos}
Variable var expanded, starting from offset pos.

So if "$@" == "4 my commit message", then:
"${@:1}" == " my commit message"
"${@:2}" == "my commit message"
As you are concatenating ${@:1} ${@:2} you are seeing my commit message twice.