Argumentos em Shell Scripts (Bourne Shell) (2)

Colaboração: Rubens Queiroz de Almeida

Data de Publicação: 01 de Junho de 1997

$#

Número de argumentos fornecidos. Constitui uma norma de boa programação verificar este valor no início da shell e emitir mensagem de erro caso incorreto.

Por exemplo:

  #!/bin/sh
  
  if [ $# -ne 2 ]; then
          echo 1>&2 Sintaxe: $0 in out
          exit 1
  fi 

No exemplo acima, se não forem fornecidos dois argumentos é exibida uma mensagem de erro para o usuário e é setado o código de retorno com o valor 1 para indicar que houve um erro de processamento.

Dica Humorística :-)

TO MY DARLING HUSBAND:

I am sending you this letter via this BBS communications thing, so that you will be sure to read it. Please forgive the deception, but I thought you should know what has been going on at home since your computer entered our lives two years ago. The children are doing well. Tommy is seven now and is a bright, handsome boy. He has developed quite an interest in the arts. He drew a family portrait for a school project, all the figures were good, and the back of your head is very realistic. You should be very proud of him.

Little Jennifer turned three in September. She looks a lot like you did at that age. She is an attractive child and quite smart. She still remembers that you spent the whole afternoon with us on her birthday. What a grand day for Jenny, despite the fact that it was stormy and the electricity was out.

I am doing well. I went blonde about a year ago, and discovered that it really is more fun! George, I mean, Mr. Wilson the department head, has, uh, taken an interest in my career and has become a good friend to us all.

I discovered that the household chores are much easier since I realized that you didn't mind being vaccumed but that feather dusting made you sneeze. The house is in good shape. I had the living room painted last spring; I'm sure you noticed it. I made sure that the painters cut holes in the drop sheet so you wouldn't be disturbed.

Well, my dear, I must be going. Uncle George, uh, Mr. Wilson, I mean, is taking us all on a ski trip and there is packing to do. I have hired a housekeeper to take care of things while we are away, she'll keep things in order, fill your coffee cup and bring your meals to your desk, just the way you like it. I hope you and the computer will have a lovely time while we are gone. Tommy, Jenny, and I will think of you often. Try to remember us while your disks are booting.

Love, Karen