Published 2023-09-08.
Time to read: 2 minutes.
Installation
The pdftk website
discusses pdktk (a F/OSS command-line program), a Windows GUI, and mentions
the book PDF Hacks.
An alternative free GUI is PDFTK Builder.
Other command-line utilties for manipulating PDF documents are:
Install the command-line pdftk program on Ubuntu:
Shell
$ yes | sudo apt install pdftk
This is the pdftk help text:
Shell
$ man pdftk pdftk.pdftk-java(1) General Commands Manual pdftk.pdftk-java(1)
NAME pdftk - A handy tool for manipulating PDF
SYNOPSIS pdftk <input PDF files | - | PROMPT> [ input_pw <input PDF owner passwords | PROMPT> ] [ <operation> <operation arguments> ] [ output <output filename | - | PROMPT> ] [ encrypt_40bit | encrypt_128bit | encrypt_aes128 ] [ allow <permissions> ] [ owner_pw <owner password | PROMPT> ] [ user_pw <user password | PROMPT> ] [ flatten ] [ need_appearances ] [ compress | uncompress ] [ keep_first_id | keep_final_id ] [ drop_xfa ] [ drop_xmp ] [ replacement_font <font name> ] [ verbose ] [ dont_ask | do_ask ] Where: <operation> may be empty, or: [ cat | shuffle | burst | rotate | generate_fdf | fill_form | background | multibackground | stamp | multistamp | dump_data | dump_data_utf8 | dump_data_fields | dump_data_fields_utf8 | dump_data_annots | update_info | update_info_utf8 | attach_files | unpack_files ]
For Complete Help: pdftk --help
DESCRIPTION If PDF is electronic paper, then pdftk is an electronic staple- remover, hole-punch, binder, secret-decoder-ring, and X-Ray- glasses. Pdftk is a simple tool for doing everyday things with PDF documents. Use it to:
* Merge PDF Documents or Collate PDF Page Scans * Split PDF Pages into a New Document * Rotate PDF Documents or Pages * Decrypt Input as Necessary (Password Required) * Encrypt Output as Desired * Fill PDF Forms with X/FDF Data and/or Flatten Forms * Generate FDF Data Stencils from PDF Forms * Apply a Background Watermark or a Foreground Stamp * Report PDF Metrics, Bookmarks and Metadata * Add/Update PDF Metrics, Bookmarks or Metadata * Attach Files to PDF Pages or the PDF Document * Unpack PDF Attachments * Burst a PDF Document into Single Pages * Uncompress and Re-Compress Page Streams * Repair Corrupted PDF (Where Possible)
OPTIONS A summary of options is included below.
--help, -h Show this summary of options.
<input PDF files | - | PROMPT> A list of the input PDF files. If you plan to combine these PDFs (without using handles) then list files in the order you want them combined. Use - to pass a sin‐ gle PDF into pdftk via stdin. Input files can be asso‐ ciated with handles, where a handle is one or more up‐ per-case letters:
<input PDF handle>=<input PDF filename>
Handles are often omitted. They are useful when speci‐ fying PDF passwords or page ranges, later.
For example: A=input1.pdf QT=input2.pdf M=input3.pdf
[input_pw <input PDF owner passwords | PROMPT>] Input PDF owner passwords, if necessary, are associated with files by using their handles:
<input PDF handle>=<input PDF file owner password>
If handles are not given, then passwords are associated with input files by order.
Most pdftk features require that encrypted input PDF are accompanied by the ~owner~ password. If the input PDF has no owner password, then the user password must be given, instead. If the input PDF has no passwords, then no password should be given.
When running in do_ask mode, pdftk will prompt you for a password if the supplied password is incorrect or none was given.
[<operation> <operation arguments>] Available operations are: cat, shuffle, burst, rotate, generate_fdf, fill_form, background, multibackground, stamp, multistamp, dump_data, dump_data_utf8, dump_data_fields, dump_data_fields_utf8, dump_data_an‐ nots, update_info, update_info_utf8, attach_files, un‐ pack_files. Some operations takes additional arguments, described below.
If this optional argument is omitted, then pdftk runs in 'filter' mode. Filter mode takes only one PDF input and creates a new PDF after applying all of the output op‐ tions, like encryption and compression.
cat [<page ranges>] Assembles (catenates) pages from input PDFs to create a new PDF. Use cat to merge PDF pages or to split PDF pages from documents. You can also use it to rotate PDF pages. Page order in the new PDF is specified by the order of the given page ranges. Page ranges are described like this:
<input PDF handle>[<begin page number>[-<end page number>[<qualifier>]]][<page rotation>]
Where the handle identifies one of the input PDF files, and the beginning and ending page numbers are one-based references to pages in the PDF file. The qualifier can be even, odd, or ~, and the page rota‐ tion can be north, south, east, west, left, right, or down.
If a PDF handle is given but no pages are specified, then the entire PDF is used. If no pages are speci‐ fied for any of the input PDFs, then the input PDFs' bookmarks are also merged and included in the output.
If the handle is omitted from the page range, then the pages are taken from the first input PDF.
The even qualifier causes pdftk to use only the even- numbered PDF pages, so 1-6even yields pages 2, 4 and 6 in that order. 6-1even yields pages 6, 4 and 2 in that order.
The odd qualifier works similarly to the even.
Pages can be subtracted from a page range using the ~ qualifier followed by a page range. For instance, 1-20~5-6 and 1-20~5~6 are equivalent to 1-4 7-20, and ~5 yields all pages except page 5. Depending on your shell, you may need to quote this argument because of the ~ at the beginning.
The page rotation setting can cause pdftk to rotate pages and documents. Each option sets the page rota‐ tion as follows (in degrees): north: 0, east: 90, south: 180, west: 270, left: -90, right: +90, down: +180. left, right, and down make relative adjustments to a page's rotation.
If no arguments are passed to cat, then pdftk com‐ bines all input PDFs in the order they were given to create the output.
NOTES: * <end page number> may be less than <begin page num‐ ber>. * The keyword end may be used to reference the final page of a document instead of a page number. * Reference a single page by omitting the ending page number. * The handle may be used alone to represent the en‐ tire PDF document, e.g., B1-end is the same as B. * You can reference page numbers in reverse order by prefixing them with the letter r. For example, page r1 is the last page of the document, r2 is the next- to-last page of the document, and rend is the first page of the document. You can use this prefix in ranges, too, for example r3-r1 is the last three pages of a PDF.
Page Range Examples without Handles: 1\-endeast – rotate entire document 90 degrees 5 11 20 – take single pages from input PDF 5-25oddwest – take odd pages in range, rotate 90 de‐ grees 6-1 – reverse pages in range from input PDF
Page Range Examples Using Handles: Say A=in1.pdf B=in2.pdf, then: A1-21 – take range from in1.pdf Bend-1odd – take all odd pages from in2.pdf in re‐ verse order A72 – take a single page from in1.pdf A1-21 Beven A72 – assemble pages from both in1.pdf and in2.pdf Awest – rotate entire in1.pdf document 90 degrees B – use all of in2.pdf A2-30evenleft – take the even pages from the range, remove 90 degrees from each page's rotation A A – catenate in1.pdf with in1.pdf Aevenwest Aoddeast – apply rotations to even pages, odd pages from in1.pdf Awest Bwest Bdown – catenate rotated documents
shuffle [<page ranges>] Collates pages from input PDFs to create a new PDF. Works like the cat operation except that it takes one page at a time from each page range to assemble the output PDF. If one range runs out of pages, it con‐ tinues with the remaining ranges. Ranges can use all of the features described above for cat, like reverse page ranges, multiple ranges from a single PDF, and page rotation. This feature was designed to help collate PDF pages after scanning paper documents.
burst Splits a single input PDF document into individual pages. Also creates a report named doc_data.txt which is the same as the output from dump_data. The output section can contain a printf-styled format string to name these pages. For example, if you want pages named page_01.pdf, page_02.pdf, etc., pass output page_%02d.pdf to pdftk. If the pattern is omitted, then a default pattern g_%04d.pdf is appended and produces pages named pg_0001.pdf, pg_0002.pdf, etc. Encryption can be applied to the output by appending output options such as owner_pw, e.g.:
pdftk in.pdf burst owner_pw foopass
rotate [<page ranges>] Takes a single input PDF and rotates just the speci‐ fied pages. All other pages remain unchanged. The page order remains unchanged. Specify the pages to rotate using the same notation as you would with cat, except you omit the pages that you aren't rotating:
[<begin page number>[-<end page number>[<quali‐ fier>]]][<page rotation>]
The qualifier can be even or odd, and the page rota‐ tion can be north, south, east, west, left, right, or down.
Each option sets the page rotation as follows (in de‐ grees): north: 0, east: 90, south: 180, west: 270, left: -90, right: +90, down: +180. left, right, and down make relative adjustments to a page's rotation.
The given order of the pages doesn't change the page order in the output.
generate_fdf Reads a single input PDF file and generates an FDF file suitable for fill_form out of it to the given output filename or (if no output is given) to stdout. Does not create a new PDF.
fill_form <FDF data filename | XFDF data filename | - | PROMPT> Fills the single input PDF's form fields with the data from an FDF file, XFDF file or stdin. Enter the data filename after fill_form, or use - to pass the data via stdin, like so:
pdftk form.pdf fill_form data.fdf output form.filled.pdf
If the input FDF file includes Rich Text formatted data in addition to plain text, then the Rich Text data is packed into the form fields as well as the plain text. Pdftk also sets a flag that cues Reader/Acrobat to generate new field appearances based on the Rich Text data. So when the user opens the PDF, the viewer will create the Rich Text appear‐ ance on the spot. If the user's PDF viewer does not support Rich Text, then the user will see the plain text data instead. If you flatten this form before Acrobat has a chance to create (and save) new field appearances, then the plain text field data is what you'll see.
Also see the flatten, need_appearances, and replace‐ ment_font options.
background <background PDF filename | - | PROMPT> Applies a PDF watermark to the background of a single input PDF. Pass the background PDF's filename after background like so:
pdftk in.pdf background back.pdf output out.pdf
Pdftk uses only the first page from the background PDF and applies it to every page of the input PDF. This page is scaled and rotated as needed to fit the input page. You can use - to pass a background PDF into pdftk via stdin.
If the input PDF does not have a transparent back‐ ground (such as a PDF created from page scans) then the resulting background won't be visible – use the stamp operation instead.
multibackground <background PDF filename | - | PROMPT> Same as the background operation, but applies each page of the background PDF to the corresponding page of the input PDF. If the input PDF has more pages than the stamp PDF, then the final stamp page is re‐ peated across these remaining pages in the input PDF.
stamp <stamp PDF filename | - | PROMPT> This behaves just like the background operation ex‐ cept it overlays the stamp PDF page on top of the in‐ put PDF document's pages. This works best if the stamp PDF page has a transparent background.
multistamp <stamp PDF filename | - | PROMPT> Same as the stamp operation, but applies each page of the background PDF to the corresponding page of the input PDF. If the input PDF has more pages than the stamp PDF, then the final stamp page is repeated across these remaining pages in the input PDF.
dump_data Reads a single input PDF file and reports its meta‐ data, bookmarks (a/k/a outlines), page metrics (me‐ dia, rotation and labels), data embedded by STAMPtk (see STAMPtk's embed option) and other data to the given output filename or (if no output is given) to stdout. Non-ASCII characters are encoded as XML nu‐ merical entities. Does not create a new PDF.
dump_data_utf8 Same as dump_data except that the output is encoded as UTF-8.
dump_data_fields Reads a single input PDF file and reports form field statistics to the given output filename or (if no output is given) to stdout. Non-ASCII characters are encoded as XML numerical entities. Does not create a new PDF.
dump_data_fields_utf8 Same as dump_data_fields except that the output is encoded as UTF-8.
dump_data_annots This operation currently reports only link annota‐ tions. Reads a single input PDF file and reports an‐ notation information to the given output filename or (if no output is given) to stdout. Non-ASCII charac‐ ters are encoded as XML numerical entities. Does not create a new PDF.
update_info <info data filename | - | PROMPT> Changes the bookmarks, page labels, page sizes, page rotations, and metadata in a single PDF's Info dic‐ tionary to match the input data file. The input data file uses the same syntax as the output from dump_data. Non-ASCII characters should be encoded as XML numerical entities.
This operation does not change the metadata stored in the PDF's XMP stream, if it has one. (For this reason you should include a ModDate entry in your updated info with a current date/timestamp, format: D:YYYYM‐ MDDHHmmSS, e.g. D:201307241346 – omitted data after YYYY revert to default values.)
For example:
pdftk in.pdf update_info in.info output out.pdf
update_info_utf8 <info data filename | - | PROMPT> Same as update_info except that the input is encoded as UTF-8.
attach_files <attachment filenames | PROMPT> [to_page <page number | PROMPT> | relation <relationship>] Packs arbitrary files into a PDF using PDF's file at‐ tachment features. More than one attachment may be listed after attach_files. Attachments are added at the document level unless the optional to_page option is given, in which case the files are attached to the given page number (the first page is 1, the final page is end). Attachments at the document level may be tagged with a relationship among Source, Data, Al‐ ternative, Supplement, and Unspecified (default).
For example:
pdftk in.pdf attach_files table1.html table2.html to_page 6 output out.pdf
pdftk in.pdf attach_files in.tex relation Source out‐ put out.pdf
unpack_files Copies all of the attachments from the input PDF into the current folder or to an output directory given after output. For example:
pdftk report.pdf unpack_files output ~/atts/
or, interactively:
pdftk report.pdf unpack_files output PROMPT
[output <output filename | - | PROMPT>] The output PDF filename may not be set to the name of an input filename. Use - to output to stdout. When using the dump_data operation, use output to set the name of the output data file. When using the unpack_files opera‐ tion, use output to set the name of an output directory. When using the burst operation, you can use output to control the resulting PDF page filenames (described above).
[encrypt_40bit | encrypt_128bit | encrypt_aes128] If an output PDF user or owner password is given, the output PDF encryption algorithm defaults to AES-128. The weaker RC4 40-bit and RC4 128-bit algorithms can be cho‐ sen by specifying encrypt_40bit or encrypt_128bit (dis‐ couraged).
[allow <permissions>] Permissions are applied to the output PDF only if an en‐ cryption strength is specified or an owner or user pass‐ word is given. If permissions are not specified, they default to 'none,' which means all of the following fea‐ tures are disabled.
The permissions section may include one or more of the following features:
Printing Top Quality Printing
DegradedPrinting Lower Quality Printing
ModifyContents Also allows Assembly
Assembly
CopyContents Also allows ScreenReaders
ScreenReaders
ModifyAnnotations Also allows FillIn
FillIn
AllFeatures Allows the user to perform all of the above, and top quality printing.
[owner_pw <owner password | PROMPT>]
[user_pw <user password | PROMPT>] If an encryption strength is given but no passwords are supplied, then the owner and user passwords remain empty, which means that the resulting PDF may be opened and its security parameters altered by anybody.
[compress | uncompress] These are only useful when you want to edit PDF code in a text editor like vim or emacs. Remove PDF page stream compression by applying the uncompress filter. Use the compress filter to restore compression.
[flatten] Use this option to merge an input PDF's interactive form fields (and their data) with the PDF's pages. Only one input PDF may be given. Sometimes used with the fill_form operation.
[need_appearances] Sets a flag that cues Reader/Acrobat to generate new field appearances based on the form field values. Use this when filling a form with non-ASCII text to ensure the best presentation in Adobe Reader or Acrobat. It won't work when combined with the flatten option.
[replacement_font <font name>] Use the specified font to display text in form fields. This option is useful when filling a form with non-ASCII text that is not supported by the fonts included in the input PDF. font name may be either the file name or the family name of a font, but using a file name is more re‐ liable. Currently only TrueType fonts with Unicode text are supported.
[keep_first_id | keep_final_id] When combining pages from multiple PDFs, use one of these options to copy the document ID from either the first or final input document into the new output PDF. Otherwise pdftk creates a new document ID for the output PDF. When no operation is given, pdftk always uses the ID from the (single) input PDF.
[drop_xfa] If your input PDF is a form created using Acrobat 7 or Adobe Designer, then it probably has XFA data. Filling such a form using pdftk yields a PDF with data that fails to display in Acrobat 7 (and 6?). The workaround solution is to remove the form's XFA data, either before you fill the form using pdftk or at the time you fill the form. Using this option causes pdftk to omit the XFA data from the output PDF form.
This option is only useful when running pdftk on a sin‐ gle input PDF. When assembling a PDF from multiple in‐ puts using pdftk, any XFA data in the input is automati‐ cally omitted.
[drop_xmp] Many PDFs store document metadata using both an Info dictionary (old school) and an XMP stream (new school). Pdftk's update_info operation can update the Info dic‐ tionary, but not the XMP stream. The proper remedy for this is to include a ModDate entry in your updated info with a current date/timestamp. The date/timestamp format is: D:YYYYMMDDHHmmSS, e.g. D:201307241346 – omitted data after YYYY revert to default values. This newer ModDate should cue PDF viewers that the Info metadata is more current than the XMP data.
Alternatively, you might prefer to remove the XMP stream from the PDF altogether – that's what this option does. Note that objects inside the PDF might have their own, separate XMP metadata streams, and that drop_xmp does not remove those. It only removes the PDF's document- level XMP stream.
[verbose] By default, pdftk runs quietly. Append verbose to the end and it will speak up.
[dont_ask | do_ask] Depending on the compile-time settings (see ASK_ABOUT_WARNINGS), pdftk might prompt you for further input when it encounters a problem, such as a bad pass‐ word. Override this default behavior by adding dont_ask (so pdftk won't ask you what to do) or do_ask (so pdftk will ask you what to do).
When running in dont_ask mode, pdftk will over-write files with its output without notice.
EXAMPLES Collate scanned pages pdftk A=even.pdf B=odd.pdf shuffle A B output collated.pdf or if odd.pdf is in reverse order: pdftk A=even.pdf B=odd.pdf shuffle A Bend-1 output col‐ lated.pdf
The following examples use actual passwords as command line pa‐ rameters, which is discouraged (see the SECURITY CONSIDERATIONS section).
Decrypt a PDF pdftk secured.pdf input_pw foopass output unsecured.pdf
Encrypt a PDF using AES-128 (the default), withhold all permis‐ sions (the default) pdftk 1.pdf output 1.128.pdf owner_pw foopass
Same as above, except password 'baz' must also be used to open output PDF pdftk 1.pdf output 1.128.pdf owner_pw foo user_pw baz
Same as above, except printing is allowed (once the PDF is open) pdftk 1.pdf output 1.128.pdf owner_pw foo user_pw baz allow printing
Apply RCA 40-bit encryption to output, revoking all permissions (the default). Set the owner PW to 'foopass'. pdftk 1.pdf 2.pdf cat output 3.pdf encrypt_40bit owner_pw foopass
Join two files, one of which requires the password 'foopass'. The output is not encrypted. pdftk A=secured.pdf 2.pdf input_pw A=foopass cat output 3.pdf
Join in1.pdf and in2.pdf into a new PDF, out1.pdf pdftk in1.pdf in2.pdf cat output out1.pdf or (using handles): pdftk A=in1.pdf B=in2.pdf cat A B output out1.pdf or (using wildcards): pdftk *.pdf cat output combined.pdf
Remove page 13 from in1.pdf to create out1.pdf pdftk in.pdf cat 1-12 14-end output out1.pdf or: pdftk A=in1.pdf cat A1-12 A14-end output out1.pdf
Uncompress PDF page streams for editing the PDF in a text edi‐ tor (e.g., vim, emacs) pdftk doc.pdf output doc.unc.pdf uncompress
Repair a PDF's corrupted XREF table and stream lengths, if pos‐ sible pdftk broken.pdf output fixed.pdf
Burst a single PDF document into pages and dump its data to doc_data.txt pdftk in.pdf burst
Burst a single PDF document into encrypted pages. Allow low- quality printing pdftk in.pdf burst owner_pw foopass allow DegradedPrinting
Write a report on PDF document metadata and bookmarks to re‐ port.txt pdftk in.pdf dump_data output report.txt
Rotate the first PDF page to 90 degrees clockwise pdftk in.pdf cat 1east 2-end output out.pdf
Rotate an entire PDF document to 180 degrees pdftk in.pdf cat 1-endsouth output out.pdf
NOTES This is a port of pdftk to java. See https://gitlab.com/pdftk-java/pdftk The original program can be found at www.pdftk.com
AUTHOR Original author of pdftk is Sid Steward (sid.steward at pdflabs dot com).
SECURITY CONSIDERATIONS Passing a password as a command line parameter is insecure be‐ cause it can get saved into the shell's history and be accessi‐ ble by other users via /proc. Use the keyword PROMPT and input any passwords via standard input instead.
December 7, 2020 pdftk.pdftk-java(1)
OCR
https://tools.pdf24.org/en/ocr-pdf provides fast, free OCR, without ads.
This website works well, and offers a total of 30 PDF operations.
The other operations of https://tools.pdf24.org/ include merging, splitting,
compressing, editing, signing, redacting, watermarking, locking, unlocking, etc.
PdfTk Operations
Rotate page 2 only
Given my_file.pdf, a 2-page document:
- Do not transform page 1 (keep it as-is)
- Rotate page 2 only
- Save as
my_file_fixed.pdf
Shell
$ pdftk my_file.pdf cat 1 2south output my_file_fixed.pdf
Merge PDFs
Concatenate file_a.pdf, file_b.pdf and file_c.pdf, then save as big_file.pdf:
Shell
$ pdftk file_a.pdf file_b.pdf file_c.pdf cat output big_file.pdf
Assemble Book Excerpt
If you need to create multiple excerpts of a book, one way to proceed is to:
-
Create a PDF containing 3 pages:
the front cover, the page containing the edition notice,
and the back cover.
Let's call this PDF file
book_wrapper.pdf. -
Scan each of the excerpts into separate PDFs.
Let's call these PDF files
book_excerpt_raw_1.pdf,book_excerpt_raw_2.pdf, etc. -
Wrap the each excerpt within the front cover and edition notice, and the back cover.
To do that, concatenate the first 2 pages of
book_wrapper.pdf,book_excerpt_raw_N.pdfand the last page ofbook_wrapper.pdf, then save asbook_excerpt_N.pdf. Following is an example of how to do that for 3 excerpts:
Shell
$ pdftk book_wrapper.pdf 1-2 \ book_excerpt_raw_1.pdf \ book_wrapper.pdf 3 \ cat output book_excerpt_1.pdf $ pdftk book_wrapper.pdf 1-2 \ book_excerpt_raw_2.pdf \ book_wrapper.pdf 3 \ cat output book_excerpt_2.pdf $ pdftk book_wrapper.pdf 1-2 \ book_excerpt_raw_3.pdf \ book_wrapper.pdf 3 \ cat output book_excerpt_3.pdf
Cut a large PDF into 2 Parts
Cut bigfile.pdf into two parts:
bigfile_part1.pdf(containing pages 1-150)bigfile_part2.pdf(containing pages 151-350)
Shell
$ pdftk A=bigfile.pdf cat 1-150 output bigfile_part1.pdf $ pdftk A=bigfile.pdf cat 151-end output bigfile_part2.pdf
Interleaving Double-Sided Originals
If you scan a double-sided document, you might end up with the odd-numbered pages in one PDF document, and the even-numbered pages in another.
A problem that you will encouter is that when you turn over the document to scan the even-numbered pages, they will be in reverse order because the pages will be scanned from the back to the front of the document. The following examples show two ways of combining the odd- and even-numbered pages in the proper order.
Manually Reversing Even-Numbered Pages
This example shows how to interleave the pages in both documents to create complete.pdf.
- Scan the paper document from front to back, so only the odd pages are saved as
odd.pdf. - Manually reverse the order of the pages in the paper document.
- Turn the paper document over.
- Scan the even pages into
even.pdf. - Run the following incantation:
Shell
$ pdftk A=odd.pdf B=even.pdf shuffle A B output complete.pdf
$ rm even.pdf odd.pdf
Automatically Reversing Even-Numbered Pages
This example does not require you to manually re-order the pages,
because pdftk can perform that task.
- Scan the document from front to back, so only the odd pages are saved as
odd.pdf. - Turn over the paper document.
- Scan the even pages from back to front into
even_reversed.pdf. - Run the following incantation:
Shell
$ pdftk even_reversed.pdf cat end-1 output even.pdf
$ pdftk A=odd.pdf B=even.pdf shuffle A B output complete.pdf
$ rm even.pdf even_reversed.pdf odd.pdf
Delete a Page
Delete page 69 from bigfile.pdf and save as smaller.pdf:
Shell
$ pdftk A=bigfile.pdf cat ~69 output smaller.pdf
Delete Several Pages
Delete pages 69-96 from bigfile.pdf and save as smaller.pdf:
Shell
$ pdftk A=bigfile.pdf cat ~69-96 output smaller.pdf
Remove Password
Assuming protected.pdf is encrypted with password myPwd, make an unencrypted copy and save as output.pdf:
Shell
$ pdftk protected.pdf input_pw myPwd output output.pdf
You might need to enclose the password within single quotes.
Edit Contents
Use LibreOffice Writer to edit the PDF, then export as PDF.
Shell
$ libreoffice --writer my_file.pdf