$ gitbook help
可以看到
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build [book] [output] build a book
--format Format to build to (Default is website; Values are website, json, ebook)
--log Minimum log level to display (Default is info; Values are debug, info, warn, error, disabled)
pdf [book] [output] build a book to pdf
--log Minimum log level to display (Default is info; Values are debug, info, warn, error, disabled)
epub [book] [output] build a book to epub
--log Minimum log level to display (Default is info; Values are debug, info, warn, error, disabled)
mobi [book] [output] build a book to mobi
--log Minimum log level to display (Default is info; Values are debug, info, warn, error, disabled)
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