10.3.10 isNumericStr (evaluates numeric characters)

Syntax

isNumericStr  character-string

Description

This command evaluates whether the character string specified for the argument can be evaluated as numeric characters.

Numeric characters have the following syntax (example: 123, -100, 001).

[-]<Numeric characters>+

This command outputs 1 in the following cases:

• The character string can be evaluated as numeric characters

This command outputs 0.

• The character string cannot be evaluated as numeric characters

Arguments

character-string

This command specifies the character string to be evaluated.

Output to the standard output

1 or 0.

Return codes

Return code	Meaning
0	Normal termination
Not less than 1	Termination with an error

Examples

isNumericStr 123      # "1" is output.
isNumericStr -100     # "1" is output.
isNumericStr 001      # "1" is output.
isNumericStr +5       # "0" is output.
isNumericStr abc      # "0" is output.

# If the value of the variable var1 cannot be evaluated, return 1.
result=$(isNumericStr "$var1")
if [[ $result -eq 0 ]]; then
  return 1
fi