我需要在我的Makefile中传入一个参数,该参数由一个形如主机标识符的字符串组成
host[:port]
冒号和端口号是可选的,因此以下所有格式都是有效的:
foo.example.com
ssl.example.com:443
localhost:5000
我想把字符串按可选冒号分隔并将值赋给变量,以便 HOST
包含 foo.example.com
、ssl.example.com
、localhost
等等,以及 PORT
包含默认端口80、443和500。
# Retrieves a host part of the given string (without port).
# Param:
# 1. String to parse in form 'host[:port]'.
host = $(firstword $(subst :, ,$1))
# Returns a port (if any).
# If there is no port part in the string, returns the second argument
# (if specified).
# Param:
# 1. String to parse in form 'host[:port]'.
# 2. (optional) Fallback value.
port = $(or $(word 2,$(subst :, ,$1)),$(value 2))
使用方法:
$(call host,foo.example.com) # foo.example.com
$(call port,foo.example.com,80) # 80
$(call host,ssl.example.com:443) # ssl.example.com
$(call port,ssl.example.com:443,80) # 443