関連ワード:  shell script check if variable is defined    shell script check if variable is set    shell script check if parameter is set    shell script check if environment variable is set    shell script check if variable exists    sh script check if environment variable is set    shell script check if env var is set    bash script check if variable is defined    sh script check if variable exists    shell script check if parameter exists  
結果 : shell script check if variable is defined