concatenate inputs in bash script [duplicate]

Answer 1

Here's a piece of code that I'm actually proud of (it is very shell-style I think)

#!/bin/sh

firsttime=yes
for i in "$@" 
do
    test "$firsttime" && set -- && unset firsttime
    test "${i%%-*}" && set -- "$@" "$i"
done

IFS=_ ; echo "$*"

I've interpreted your question so as to remove all arguments beginning with -

If you only want to remove the beginning sequence of arguments beginnnig with -:

#!/bin/sh

while ! test "${1%%-*}"
do
    shift
done

IFS=_ ; echo "$*"

If you simply want to remove the first argument:

#!/bin/sh

shift
IFS=_ ; printf %s\\n "$*"

Answer 2

function concatenate_args
{
    string=""
    for a in "$@" # Loop over arguments
    do
        if [[ "${a:0:1}" != "-" ]] # Ignore flags (first character is -)
        then
            if [[ "$string" != "" ]]
            then
                string+="_" # Delimeter
            fi
            string+="$a"
        fi
    done
    echo "$string"
}

# Usage:
args="$(concatenate_args "$@")"

Answer 3

flag="$1"
shift
oldIFS="$IFS"
IFS="_"
the_rest="$*"
IFS="$oldIFS"

In this context, "$*" is exactly what you're looking for, it seems. It is seldom the correct choice, but here's a case where it really is the correct choice.

Alternatively, simply loop and concatenate:

flag="$1"
shift
the_rest=""
pad=""
for arg in "$@"
do
    the_rest="${the_rest}${pad}${arg}"
    pad="_"
done

The $pad variable ensures that you don't end up with a stray underscore at the start of $the_rest.

Answer 4

You can also use formatted strings to concatenate args.

# assuming flag is first arg and optional
flag=$1
[[ $1 = ${1#-} ]] && unset $flag || shift

concat=$(printf '%s_' ${@})
echo ${concat%_} # to remove the trailing _

nJoy!

Answer 5

This is an ugly but simple solution:

echo $* | sed -e "s/ /_/g;s/[^_]*_//"

Answer 6

#!/bin/bash
paramCat () {
for s in "$@" 
do
    case $s in 
        -*)
            ;;
        *) 
            echo -n _${s}
            ;; 
    esac
done
}

catted="$(paramCat "$@")"
echo ${catted/_/}