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【已解决】Makefile中如何判断一个字符串变量存在另外一个字符串或列表中

makefile crifan 94浏览 0评论

折腾:

【已解决】更新gitbook发布脚本Makefile忽略某些book

期间,接着需要想办法如何从字符串获取到列表

或者去判断,某个字符串 是否在 一个字符串中

deploy_ignore_book_crifan_com.txt

test_book_name_1
scientific_network_summary
test_book_name_2

然后希望拿到一个变量是scientific_network_summary

能够判断,是否在上述的字符串中

makefile check contain string

Makefile : contains string – Stack Overflow

findstring

貌似就够用了?

GNU-make check if element exists in list/array – Stack Overflow

说是用filter

GNU make: Text Functions

“$(findstring find,in)

Searches in for an occurrence of find. If it occurs, the value is find; otherwise, the value is empty. You can use this function in a conditional to test for the presence of a specific substring in a given string. Thus, the two examples,

$(findstring a,a b c)

$(findstring a,b c)

produce the values ‘a’ and ‘’ (the empty string), respectively. See Testing Flags, for a practical application of findstring.

$(filter pattern…,text)

Returns all whitespace-separated words in text that do match any of the pattern words, removing any words that do not match. The patterns are written using ‘%’, just like the patterns used in the patsubst function above.

The filter function can be used to separate out different types of strings (such as file names) in a variable. For example:

sources := foo.c bar.c baz.s ugh.h

foo: $(sources)

        cc $(filter %.c %.s,$(sources)) -o foo

says that foo depends of foo.c, bar.c, baz.s and ugh.h but only foo.c, bar.c and baz.s should be specified in the command to the compiler.”

突然发现:findstring

不适合此处,此处的in是要一个list才行

How to check whether a variable contains spaces in a Makefile ? – Stack Overflow

先去试试再说

$(info IGNORE_FILE_CONTENT=$(IGNORE_FILE_CONTENT))
$(info BOOK_NAME=$(BOOK_NAME))
FOUND_BOOK = $(findstring $(BOOK_NAME), $(IGNORE_FILE_CONTENT))
$(info FOUND_BOOK=$(FOUND_BOOK))

是可以找到的:

IGNORE_FILE_CONTENT=test_book_name_1 scientific_network_summary test_book_name_2
BOOK_NAME=scientific_network_summary
FOUND_BOOK=scientific_network_summary

后续继续去判断是否为空

【已解决】Makefile中判断变量是否为空无效

【总结】

最后用:

FOUND_BOOK := $(findstring $(BOOK_NAME), $(IGNORE_FILE_CONTENT))

实现了,去判断

BOOK_NAME=scientific_network_summary

的确是在:

IGNORE_FILE_CONTENT

的值是:

scientific_network_summary

能够找到,并返回

scientific_network_summary

否则就返回Empty=None=null=空

注意不是空字符串。

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