1

I want to use an argument in the function I created in my .profile file.

I want to ask for input if no argument is given, otherwise set a variable to $1.

When I check $1 to see if it is empty, I get the following error:

sh[7]: 1: Parameter not set.

From the following line:

if [ ! -n "$1" ]; then

I'm using sh not bash.

EDIT: Ok, here is the first line of code until the end of the if statement:

HOST=`hostname`
cd /opt/dirpath
ll *.sto


if [ x"$1" = x ]; then
  # Ask for input
  echo "File: \c"; read outFile
else
    outFile=$1
fi

I'm editing someone else's code to work with or without arguments.

Improve this question
6
  • the way I've seen this done is if [ "x$1" = "x" ]; then ... there is no parameter Commented Jul 9, 2015 at 16:01
  • As @JeffSchaller points out, the [[ ... ]] construct is a bash extension, you need to use if [ x"$1" = x ] instead. Commented Jul 9, 2015 at 16:43
  • Do you use set -e? Commented Jul 9, 2015 at 16:47
  • James, I see you edited the script to remove square brackets after lcd047's comment. After reading mikeserv's answer, I think it would be worthwhile to see more or all of your .profile so that we know what's going on. Commented Jul 9, 2015 at 18:40
  • 1
    @JeffSchaller - $1 is the parameter. The error message says so. It says: [LINENO]: PARAM_NAME: DEFAULT ERROR MESSAGE.. Try it. Try: unset my_var_name; echo "${my_var_name?"My error message."}". And to test if a var is set or unset just do [ -z "${var+.}" ] Commented Jul 9, 2015 at 19:19

1 Answer 1

Reset to default
2

I think there's more to this:

Either that's not the command you're using - or else somewhere else in the function you're doing it differently. That error comes from ${1?}. Or it comes from your test, but only if you first do set -u.

To fix that, stop doing that. Do set +u; fn_name, and see what happens. And if you have any ${1?} expansions in there, that error will not go away until you give the function an argument.

Here are some code examples of how you might reproduce that error:

sh -c 'fn(){ [ ! -n "${1?}" ]; }; fn'
sh: 1: 1: parameter not set

...or...

sh -uc 'fn(){ [ ! -n "$1" ]; }; fn'
sh: 1: 1: parameter not set

...but...

sh -uc 'fn(){ [ ! -n "$1" ]; }
        set +u; fn; echo "$?"'
0

...and...

sh -c 'fn(){ [ ! -n "${1?}" ]; }
       fn some args; echo "$?"'
1

If the function is setting -u then you should probably edit that out. Or else if your .profile is doing so, same goes. In most cases, set -u is not a desirable persistent shell setting, and this is because that mode is designed to kill shells. It does not provide any simple means of handling the kinds of errors it generates - which is what you're trying to do with [ test ].

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1
  • 1
    @James - I am still very curious - how did it get set -u? I can imagine that a curious man sh reader might notice it in passing and try it then forget it later... (it's how I learned of it after all...) Anyway, you don't need to do that [ "$1x" thing - it doesn't actually tell you if you have got an argument or not anyway. You could get a null first arg and a not-null $2 for example. I think what you want is either [ -n "${1+.}" ] || echo... or [ "$#" = 0 ] && echo ... And, about -u - you can echo "$-" to see a list of currently actove shell options anytime. Commented Jul 10, 2015 at 13:21

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