在 Makefile 中，有没有办法使用 @echo 或 $(info) 打印美元符号 ($)？

Question

我一直在尝试使用 Makefile 中使用的 @echo 和 $(info ) 将美元符号 ($) 打印到标准输出，但没有成功。

我可以在命令行的 bash shell 中使用 echo 命令打印 $ 符号，没有任何问题。但是从 Makefile 中执行时，相同的 bash 命令无法按预期工作。

以下是我的测试Makefile:

noecho:
    $(info Print the dollar sign using info: $)
    @echo You only see this!  You DO NOT see the echo command printed above.
    @echo Remember echo is a shell command. 
    @echo You may need to escape special characters, like \
    @echo 'Or put put text in single quotes! No need to escape special characters like \.'
    @echo 
    @echo "Enclosing characters in single quotes (') preserves the literal value of "
    @echo 'each character within the quotes. A single quote may not occur between '
    @echo 'single quotes, even when preceded by a backslash.'
    @echo
    @echo "Double quotes can also be used in most cases."
    @echo "Enclosing characters in double quotes (\") preserves the literal value of "
    @echo "all characters within the quotes, with the exception of $, \`, \, and, "
    @echo "when history expansion is enabled, !"
    @echo 'Printing the $'

当我执行 make noecho 时，我得到：

rob$ make noecho
Print the dollar sign using info: 
You only see this! You DO NOT see the echo command printed above.
Remember echo is a shell command.
You may need to escape special characters, like \
Or put put text in single quotes! No need to escape special characters like \.

Enclosing characters in single quotes (') preserves the literal value of 
each character within the quotes. A single quote may not occur between 
single quotes, even when preceded by a backslash.

Double quotes can also be used in most cases.
Enclosing characters in double quotes (") preserves the literal value of 
all characters within the quotes, with the exception of  `, \, and, 
when history expansion is enabled, !
/opt/local/bin/bash: -c: line 1: unexpected EOF while looking for matching `''
/opt/local/bin/bash: -c: line 2: syntax error: unexpected end of file
make: *** [noecho] Error 2

我也试过@echo "'$'"和@echo "$"都没有成功。

有没有办法在 Makefile 中使用 @echo 或 $(info ) 打印美元符号 ($)？

Answer 1

将美元符号加倍以阻止 make 对其进行解释

echo $$
$(info $$)

在 Makefile 中，有没有办法使用 @echo 或 $(info) 打印美元符号 ($)？

In Makefiles, Is there a way to print the dollar sign ($) using @echo or $(info )?

bash

makefile

gnu-make