Tcl Requires Chilkat v11.7.0+

Extract Text from a Password-Protected PDF

See more PDF Text Extraction Examples

Demonstrates extracting text from a PDF that requires a password to open. The PDF loads without the password (its structure can be read), but the "text" operation fails because the content cannot be decrypted; "assess" reports that a password is required. With the UserPassword property set before loading, extraction works normally. Tcl

load ./chilkat.dll

set success 0

#  This example requires the Chilkat API to have been previously unlocked.
#  See Global Unlock Sample for sample code.

#  The PDF used in this example (user password: secret) is available at encrypted_user_password.pdf

set pdf [new_CkPdf]

set json [new_CkJsonObject]

set jsonOut [new_CkJsonObject]

#  The PDF loads without its password: the file's structure is readable, so properties such as
#  NumPages and the security settings are available...
set success [CkPdf_LoadFile $pdf "qa_data/pdf/encrypted_user_password.pdf"]
if {$success == 0} then {
    puts [CkPdf_lastErrorText $pdf]
    delete_CkPdf $pdf
    delete_CkJsonObject $json
    delete_CkJsonObject $jsonOut
    exit
}

#  ...but the content cannot be decrypted, so extracting text fails.
set success [CkPdf_ExtractText $pdf "text" $json $jsonOut]
if {$success == 0} then {
    puts "Cannot extract: [CkPdf_lastErrorText $pdf]"
}

#  "assess" still works: it reports that a password is required and nothing else.
set success [CkPdf_ExtractText $pdf "assess" $json $jsonOut]
if {$success == 0} then {
    puts [CkPdf_lastErrorText $pdf]
    delete_CkPdf $pdf
    delete_CkJsonObject $json
    delete_CkJsonObject $jsonOut
    exit
}

puts "passwordRequired: [CkJsonObject_BoolOf $jsonOut quality.passwordRequired]"
puts "rating: [CkJsonObject_stringOf $jsonOut quality.rating]"

#  Set the password and load again.
CkPdf_put_UserPassword $pdf "secret"
set success [CkPdf_LoadFile $pdf "qa_data/pdf/encrypted_user_password.pdf"]
if {$success == 0} then {
    puts [CkPdf_lastErrorText $pdf]
    delete_CkPdf $pdf
    delete_CkJsonObject $json
    delete_CkJsonObject $jsonOut
    exit
}

set success [CkPdf_ExtractText $pdf "text" $json $jsonOut]
if {$success == 0} then {
    puts [CkPdf_lastErrorText $pdf]
    delete_CkPdf $pdf
    delete_CkJsonObject $json
    delete_CkJsonObject $jsonOut
    exit
}

puts [CkJsonObject_stringOf $jsonOut text]

#  Sample output:

#  Cannot extract: ChilkatLog:
#    ExtractText:
#      ...
#        The PDF is encrypted and could not be opened (wrong or missing password); its text cannot be read.
#      ...
#  passwordRequired: true
#  rating: none
#  Board Minutes (Confidential)
#  
#  The board met on 3 November 2026. Present: the chair, the treasurer and four members. The treasurer reported that spending for the season came in under budget.
#  
#  The meeting closed at 8.45 p.m.

delete_CkPdf $pdf
delete_CkJsonObject $json
delete_CkJsonObject $jsonOut