How to use the command pdfgrep (with examples)
PDFgrep is a command-line utility that allows you to search for text within PDF files. It provides various options to customize the search, such as case-insensitivity, specifying the maximum number of matches, and recursive searching.
Use case 1: Find lines that match a pattern in a PDF
Code:
pdfgrep pattern file.pdf
Motivation: This use case is useful when you want to find specific lines or text within a PDF file. By providing a pattern, you can narrow down the search to only the lines that match that pattern.
Explanation:
pdfgrep: The command itself.pattern: The text pattern or regular expression you want to search for.file.pdf: The PDF file in which you want to search for the pattern.
Example output:
$ pdfgrep example file.pdf
file.pdf:1:This is an example file.
file.pdf:10:Another example line.
Use case 2: Include file name and page number for each matched line
Code:
pdfgrep --with-filename --page-number pattern file.pdf
Motivation: Sometimes you might want to have more information about the context of the matched lines. Including the file name and page number helps to provide better context.
Explanation:
--with-filename: This option tells pdfgrep to include the file name in the output.--page-number: This option tells pdfgrep to include the page number where the match occurred.pattern: The text pattern or regular expression you want to search for.file.pdf: The PDF file in which you want to search for the pattern.
Example output:
$ pdfgrep --with-filename --page-number example file.pdf
file.pdf:1:This is an example file. (page 1)
file.pdf:10:Another example line. (page 2)
Use case 3: Do a case-insensitive search for lines starting with “foo” and return the first 3 matches
Code:
pdfgrep --max-count 3 --ignore-case '^foo' file.pdf
Motivation: In some cases, you might want to perform a case-insensitive search. This use case is specifically searching for lines that start with “foo” in a case-insensitive manner and returns the first 3 matches.
Explanation:
--max-count 3: This option limits the output to the first 3 matches.--ignore-case: This option tells pdfgrep to perform a case-insensitive search.^foo: This is a regular expression that matches lines starting with “foo”.file.pdf: The PDF file in which you want to search for the pattern.
Example output:
$ pdfgrep --max-count 3 --ignore-case '^foo' file.pdf
This is a Foobar.
Foobaz line.
foo123 line.
Use case 4: Find pattern in files with a .pdf extension in the current directory recursively
Code:
pdfgrep --recursive pattern
Motivation: When you have a collection of PDF files in a directory and its subdirectories, this use case allows you to search for a specific pattern in all those files without having to specify each file name individually.
Explanation:
--recursive: This option tells pdfgrep to search for files recursively in the current directory.pattern: The text pattern or regular expression you want to search for.
Example output:
$ pdfgrep --recursive example
./file.pdf:1:This is an example file.
./dir/subfile.pdf:5:Another example line.
Use case 5: Find pattern in files that match a specific glob in the current directory recursively
Code:
pdfgrep --recursive --include '*book.pdf' pattern
Motivation: When you want to search for a pattern only in PDF files with a specific naming pattern, this use case comes in handy. In this case, it searches for the pattern in all PDF files with names ending in “book.pdf”.
Explanation:
--recursive: This option tells pdfgrep to search for files recursively in the current directory.--include '*book.pdf': This option allows you to specify a glob pattern to match only specific files. In this case, it matches files that end with “book.pdf”.pattern: The text pattern or regular expression you want to search for.
Example output:
$ pdfgrep --recursive --include '*book.pdf' example
./book.pdf:1:This is an example book.
./dir/book.pdf:15:Another example book.
Conclusion:
PDFgrep is a powerful command-line tool for searching text within PDF files. Its various options allow for flexible and customizable searches, making it a useful utility for anyone who works with PDF documents regularly. Whether you need to find specific lines, search case-insensitively, or perform recursive searches, pdfgrep has got you covered.
