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
“$(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
【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。