! expect return $ESYNTAX
< ! include-file=
< ! include $include-file
-$ ./tesh --log='log.thresh:info tesh.fmt:%m%n'
+$ ./tesh --log="log.thresh:info tesh.fmt:%m%n"
> Test unit from stdin
> [stdin:1] Undefined variable `(include-file)'
-> Test unit `(stdin)' : NOK (syntax error)
+> Test unit `stdin': NOK (<stdin:1> syntax error)
# A single sample of the usage of the tesh variables
! expect return $ESYNTAX
< ! ENOENT=300
< $ echo $ENOENT
-$ ./tesh --log='log.thresh:info tesh.fmt:%m%n'
+$ ./tesh --log="log.thresh:info tesh.fmt:%m%n"
> Test unit from stdin
> [stdin:1] A system variable named `(ENOENT)' already exists
-> Test unit `(stdin)' : NOK (syntax error)
+> Test unit `stdin': NOK (<stdin:1> syntax error)
+# Substitution usage
+! new=1
+p new is `$new ' or `${new}'
+p the len of new is : ${#new}
+! unset new
+p new is empty <$new> and is len is <${#new}>
+# display 66 and assign 66 to the value 66 of the variable new
+p ${new:=66}
+p new is `$new ' or `${new}'
+p the len of new is : ${#new}
+# display 66 and do not assign the value 69 to the variable
+p ${new:=69}
+p new is `$new ' or `${new}'
+p the len of new is : ${#new}
+! unset new
+# display 79 and do not assigne the value 79 to the variable
+# new is empty
+p ${new:-79}
+p new is `$new ' or `${new}'
+p the len of new is : ${#new}
+# display nothing and do not assigne the value 89 to the variable
+# new is empty
+p is empty ${new:+89}
+p new is `$new ' or `${new}'
+p the len of new is : ${#new}
+! set new=999
+# display 99 and do not assigne the value 99 to the variable (do not dispaly the value of new)
+# new is empty
+p is empty ${new:+99}
+p new is `$new ' or `${new}'
+p the len of new is : ${#new}
+
+! unset new
+
+# p ${new:?new is empty}
