CODEWITHSUNDEEP
stringshellvariables
Gery
Gery

Reputation: 9046

question mark (?) in shell variable

I want to use a variable with this name: topMiddleOligocenetoUpperEocene?

how can I do it in a shell script (i.e., using the question mark)? I tried:

{topMiddleOligocenetoUpperEocene?}="something"

but it's not understood in my shell script (myfile.sh using in the first row #!/bin/sh).

Any hint will be appreciated, thanks in advance.

Upvotes: 2

Views: 4247

Answers (3)

anubhava
anubhava

Reputation: 785481

No you cannot use ? in unix shell variable names. In fact many other special characters such as period, comma, ? aren't allowed.

This is the regex for shell variable names:

[a-zA-Z_][a-zA-Z0-9_]*

Upvotes: 4

NeronLeVelu
NeronLeVelu

Reputation: 10039

? cannot be part of a variable name like : % = and lot more special meaning for shell. In this case it will try to find a file starting with your variable name and 1 character (any character). Unless you have one that can be executed by hte environment, it will return an error. 

ksh:
{topMiddleOligocenetoUpperEocene?}="something"
sh: {topMiddleOligocenetoUpperEocene?}=something:  not found.

bash
{topMiddleOligocenetoUpperEocene?}="something"
bash: {topMiddleOligocenetoUpperEocene?}=something: command not found

Upvotes: 0

glenn jackman
glenn jackman

Reputation: 247012

Can't. That's not a valid identifier in bash. See the definition of name at http://www.gnu.org/software/bash/manual/bashref.html#Definitions

name

A word consisting solely of letters, numbers, and underscores, and beginning with a letter or underscore. Names are used as shell variable and function names. Also referred to as an identifier.

Upvotes: 5

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