Preview the first n characters of each EPUB e-book section.
Arguments
- x
a data frame returned by
epubor a character string giving the EPUB filename(s).- n
integer, first n characters to retain from each e-book section.
Details
This function returns a simplified data frame of only the unnested section and text columns of a data frame returned by epub, with the text included only up to the first n characters.
This is useful for previewing the opening text of each e-book section to inspect for possible useful regular expression patterns to use for text-based section identification.
For example, an e-book may not have meaningful section IDs that distinguish one type of book section from another, such as chapters from non-chapter sections,
but the text itself may contain this information at or near the start of a section.
Examples
# \donttest{
file <- system.file("dracula.epub", package = "epubr")
epub_head(file)
#> # A tibble: 15 × 2
#> section text
#> <chr> <chr>
#> 1 item6 "The Project Gutenberg EBook of Dracula, by Bram St"
#> 2 item7 "But I am not in heart to describe beauty, for when"
#> 3 item8 "\" 'Lucy, you are an honest-hearted girl, I know. I"
#> 4 item9 "CHAPTER VIIIMINA MURRAY'S JOURNAL\nSame day, 11 o'c"
#> 5 item10 "CHAPTER X\nLetter, Dr. Seward to Hon. Arthur Holmwo"
#> 6 item11 "Once again we went through that ghastly operation."
#> 7 item12 "CHAPTER XIVMINA HARKER'S JOURNAL\n23 September.-Jon"
#> 8 item13 "CHAPTER XVIDR. SEWARD'S DIARY-continued\nIT was jus"
#> 9 item14 "\"Thus when we find the habitation of this man-that"
#> 10 item15 "\"I see,\" I said. \"You want big things that you can"
#> 11 item16 "CHAPTER XXIIIDR. SEWARD'S DIARY\n3 October.-The tim"
#> 12 item17 "CHAPTER XXVDR. SEWARD'S DIARY\n11 October, Evening."
#> 13 item18 " \nLater.-Dr. Van Helsing has returned. He has got "
#> 14 item19 "End of the Project Gutenberg EBook of Dracula, by "
#> 15 coverpage-wrapper ""
# }