$ sudo apt install libgcrypt20-dev libpoppler-cpp-dev
$ git clone https://gitlab.com/pdfgrep/pdfgrep
$ cd pdfgrep
$ ./autogen.sh
$ ./configure --prefix=$HOME/usr/local
$ make
$ make install

$ pdfgrep --help
Usage: ./src/pdfgrep [OPTION]... PATTERN FILE...

Search for PATTERN in each FILE.
PATTERN is, by default, an extended regular expression.

Commonly used options:
 -i, --ignore-case              Ignore case distinctions
 -P, --perl-regexp              Use Perl compatible regular expressions (PCRE)
 -H, --with-filename            Print the file name for each match
 -h, --no-filename              Suppress the prefixing of file name on output
 -n, --page-number              Print page number with output lines
 -c, --count                    Print only a count of matches per file
     --color WHEN               Use colors for highlighting;
                                WHEN can be `always', `never' or `auto'
 -p, --page-count               Print only a count of matches per page
 -m, --max-count NUM            Stop reading after NUM matching lines (per file)
 -q, --quiet                    Suppress normal output
 -r, --recursive                Search directories recursively
 -R, --dereference-recursive    Likewise, but follow all symlinks
     --cache                    Use cache for faster operation
     --help                     Print this help
 -V, --version                  Show version information

The above list is only a selection of commonly used options. Please refer
to the man page for a complete list.

$ pdfgrep raspberry ~/Downloads/MagPi128.pdf | head
raspberrypi.com
                       magpi@raspberrypi.com
                       forums.raspberrypi.com
                                                     lucy@raspberrypi.com
                                                     rob@raspberrypi.com
                                                     charlotte.milligan@raspberrypi.com
                                                     brian.jepson@raspberrypi.com
 Learn Sense HAT             magpi@raspberrypi.com             (CC BY-NC-SA 3.0).

$ pdfgrep -m5 -n -i raspberry ~/Downloads/MagPi128.pdf
1:Issue 128     April 2023   magpi.cc    The official Raspberry Pi magazine
1:   Discover coding with Raspberry Pi
1:            NEW! RASPBERRY PI GLOBAL SHUTTER CAMERA
2: Industrial Raspberry Pi
3:(page 44) can help you out on this journey. I hope you take it.                 Raspberry Pi office
                                     This Month in Raspberry Pi

$ pdfgrep -r -m1 -n サーバー ~/Nextcloud_matoken\@files.matoken.org/Linux/2025/
/home/matoken/Nextcloud_matoken@files.matoken.org/Linux/2025//sakura-cominuty-2025/snac-kagolug.pdf:2:サーバー設定ファイルの server.json を編集します。 "protocol" を
/home/matoken/Nextcloud_matoken@files.matoken.org/Linux/2025//kagolug2025.08/slide/slide.pdf:1:  ルサーバーの
/home/matoken/Nextcloud_matoken@files.matoken.org/Linux/2025//kagolug2025.09/slide/slide.pdf:19:ActivityPubも少し探したが，自分とサーバーの落ちているものしか
/home/matoken/Nextcloud_matoken@files.matoken.org/Linux/2025//kagolug2025.09/slide/matoken-slide.pdf:19:ActivityPubも少し探したが，自分とサーバーの落ちているものしか
/home/matoken/Nextcloud_matoken@files.matoken.org/Linux/2025//kagolug2025.10/slide/slide.pdf:10:     2     サーバー設定ファイルを編集．"protocol" を "http"

$ pdftotext ~/Downloads/RetroBSD_and_LiteBSD.pdf - | grep -m5 -n -i retro
1:RetroBSD and LiteBSD:
15:  Contributing to RetroBSD since 2013
30:  RetroBSD: an OS from the past in 128k RAM
35:
   RetroBSD and LiteBSD: an overview
39:  RetroBSD: PIC32MX
$ pdfgrep -m5 -n -i retro ~/Downloads/RetroBSD_and_LiteBSD.pdf
1:RetroBSD and LiteBSD:
3:  Contributing to RetroBSD since 2013
4:  RetroBSD: an OS from the past in 128k RAM
5:RetroBSD and LiteBSD: an overview
5:     RetroBSD: PIC32MX

$ apt-cache search pdfgrep
pdfgrep - 正規表現にマッチする文字列を pdf ファイル内で検索
$ rmadison pdfgrep
pdfgrep    | 2.1.2-1       | oldoldstable   | source, amd64, arm64, armhf, i386
pdfgrep    | 2.1.2-1       | oldstable      | source, amd64, arm64, armel, armhf, i386, mips64el, mipsel, ppc64el, s390x
pdfgrep    | 2.2.0-0.1     | stable         | source
pdfgrep    | 2.2.0-0.1     | testing        | source
pdfgrep    | 2.2.0-0.1     | unstable       | source
pdfgrep    | 2.2.0-0.1     | unstable-debug | source
pdfgrep    | 2.2.0-0.1+b2  | stable         | amd64, arm64, armel, armhf, i386, ppc64el, riscv64, s390x
pdfgrep    | 2.2.0-0.1+b2  | testing        | amd64, arm64, armhf, i386, ppc64el, riscv64, s390x
pdfgrep    | 2.2.0-0.1+b2  | unstable       | amd64, arm64, armhf, i386, ppc64el, riscv64, s390x
$ sudo apt install pdfgrep
$ /usr/bin/pdfgrep -V
This is pdfgrep version 2.2.0.

Using poppler version 25.03.0
Using libpcre2 version 10.46 2025-08-27

$ pdfgrep -V
This is pdfgrep version 2.2.0.

Using poppler version 25.03.0
Using libpcre2 version 10.46 2025-08-27
Built from git-commit v2.2.0-7-gaa71955
$ /usr/bin/pdfgrep -V
This is pdfgrep version 2.2.0.

Using poppler version 25.03.0
Using libpcre2 version 10.46 2025-08-27
$ dpkg-query -W poppler-utils
poppler-utils   25.03.0-11.1+b1
$ pdftotext -v
pdftotext version 25.03.0
Copyright 2005-2025 The Poppler Developers - http://poppler.freedesktop.org
Copyright 1996-2011, 2022 Glyph & Cog, LLC
$ lsb_release -dr
Description:    Debian GNU/Linux forky/sid
Release:        n/a
$ arch
x86_64

$ convert  2530201/* 宇宙船ビーグル号の冒険.pdf (1)
  :
convert-im6.q16: cache resources exhausted `2530201/2530201-107.jpg' @ error/cache.c/OpenPixelCache/4119.
convert-im6.q16: TooManyExceptions (exception processing is suspended) @ warning/exception.c/ThrowException/1054.
convert-im6.q16: cache resources exhausted `2530201/2530201-108.jpg' @ error/cache.c/OpenPixelCache/4119.
$ identify -list resource (2)
Resource limits:
  Width: 32KP
  Height: 32KP
  List length: unlimited
  Area: 256MP
  Memory: 1GiB
  Map: 2GiB
  Disk: 2GiB
  File: 768
  Thread: 4
  Throttle: 0
  Time: unlimited
$ identify -limit memory 4096MiB -list resource | grep ^\ \ Memory: (3)
  Memory: 1GiB
$ identify -limit memory 512MiB -list resource | grep ^\ \ Memory: (4)
  Memory: 512MiB
$ sudo git -C /etc diff /etc/ImageMagick-6/policy.xml (5)
diff --git a/ImageMagick-6/policy.xml b/ImageMagick-6/policy.xml
index 4b878ce..aa54cbe 100644
--- a/ImageMagick-6/policy.xml
+++ b/ImageMagick-6/policy.xml
@@ -95,7 +95,7 @@
   <!-- Set maximum amount of memory in bytes to allocate for the pixel cache
        from the heap. When this limit is exceeded, the image pixels are cached
        to memory-mapped disk. -->
-  <policy domain="resource" name="memory" value="1024MiB"/>
+  <policy domain="resource" name="memory" value="4096MiB"/>
   <!-- Set maximum amount of memory map in bytes to allocate for the pixel
        cache. When this limit is exceeded, the image pixels are cached to
        disk. -->
$ identify -list resource | grep ^\ \ Memory: (6)
  Memory: 4GiB

$ sudo apt install img2pdf (1)
$ img2pdf -o 宇宙船ビーグル号の冒険-img2pdf.pdf 2530201/* (2)
find 2530201 -type f -print0 | sort -Vz | xargs -0 img2pdf -o 宇宙船ビーグル号の冒険.pdf (3)

$ time convert 2530201/* 宇宙船ビーグル号の冒険.pdf

real    5m18.636s
user    0m47.748s
sys     0m31.136s
$ time img2pdf -o 宇宙船ビーグル号の冒険-img2pdf.pdf 2530201/*

real    0m1.279s
user    0m0.556s
sys     0m0.180s

$ dpkg-query -W imagemagick img2pdf
imagemagick     8:6.9.12.98+dfsg1-5.2
img2pdf 0.5.1-1
$ lsb_release -a
No LSB modules are available.
Distributor ID: Debian
Description:    Debian GNU/Linux trixie/sid
Release:        n/a
Codename:       trixie
$ arch
x86_64

               chromium --user-data-dir=$TMPDIR --headless --disable-gpu --print-to-pdf="${PDF}" "$URL?print-pdf"; \

$ firefox --screenshot /tmp/page.png --window-size=1280 "file:///`pwd`/slide.html#print-pdf"

$ wkhtmltopdf --enable-local-file-access --orientation Landscape --page-size B5 --margin-top 0 --margin-bottom 0 --margin-right 0 --margin-left 0 "file://`pwd`/slide/slide.html?print-pdf" /tmp/slide.pdf

$ chromium --headless --run-all-compositor-stages-before-draw --virtual-time-budget=9999999 --print-to-pdf=/tmp/slide.pdf file://`pwd`/slide/slide.html?print-pdf

-               chromium --user-data-dir=$TMPDIR --headless --disable-gpu --print-to-pdf="${PDF}" "$URL?print-pdf"; \
+               chromium --user-data-dir=$TMPDIR --headless --run-all-compositor-stages-before-draw --virtual-time-budget=999999 --print-to-pdf="${PDF}" "$URL?print-pdf"; \

$ dpkg-query -W chromium firefox-esr wkhtmltopdf
chromium        107.0.5304.110-2
firefox-esr     102.5.0esr-1
wkhtmltopdf     0.12.6-2+b1
$ lsb_release -dc
No LSB modules are available.
Description:    Debian GNU/Linux bookworm/sid
Codename:       bookworm
$ arch
x86_64

$ sudo apt install mupdf-tools

$ dpkg-query -W mupdf-tools mcomix
mcomix  1.2.1mcomix3+git20200206-1
mupdf-tools     1.20.0+ds1-1
$ lsb_release -dr
Description:    Debian GNU/Linux bookworm/sid
Release:        unstable
$ arch
x86_64

[quote,'link:https://files.matoken.org/index.php/s/r7jEJdjiSRzb4nZ[https://files.matoken.org/index.php/s/r7jEJdjiSRzb4nZ]']
link:https://files.matoken.org/index.php/s/r7jEJdjiSRzb4nZ[image:https://files.matoken.org/index.php/s/r7jEJdjiSRzb4nZ/preview[width=100%]]

<div class="quoteblock">
<blockquote>
<a href="https://files.matoken.org/index.php/s/r7jEJdjiSRzb4nZ"><span class="image"><img src="https://files.matoken.org/index.php/s/r7jEJdjiSRzb4
nZ/preview" alt="preview" width="100%"></span></a>
<div class="attribution">
&#8212; <a href="https://files.matoken.org/index.php/s/r7jEJdjiSRzb4nZ">https://files.matoken.org/index.php/s/r7jEJdjiSRzb4nZ</a>
</div>
</blockquote>
</div>

$ sudo -u www-data php occ --version
Nextcloud 20.0.8
$ dpkg-query -W php mariadb-server apache2
apache2 2.4.38-3+deb10u4
mariadb-server  1:10.3.27-0+deb10u1
php     2:7.3+69
$ lsb_release -dr
Description:    Debian GNU/Linux 10 (buster)
Release:        10
$ uname -m
x86_64

$ w3m -o display_link_number=1 https://www.oreilly.co.jp/library/4873112699/ | grep \\.pdf$ | grep -v catalog | cut -f2 -d\  | wget --wait=30 --random-wait -i - (1)
$ wget https://www.oreilly.co.jp/books/images/picture_large4-87311-269-9.jpeg (2)
$ convert ./picture_large4-87311-269-9.jpeg ./hyoushi.pdf (3)
$ ls *.pdf
appA.pdf  ato.pdf   ch03.pdf  ch06.pdf  ch09.pdf  ch12.pdf      index.pdf
appB.pdf  ch01.pdf  ch04.pdf  ch07.pdf  ch10.pdf  contents.pdf  mae.pdf
appC.pdf  ch02.pdf  ch05.pdf  ch08.pdf  ch11.pdf  hyoushi.pdf   maegaki.pdf
$ pdftk ./hyoushi.pdf ./mae.pdf ./maegaki.pdf ./contents.pdf ./ch01.pdf ./ch02.pdf ./ch03.pdf ./ch04.pdf ./ch05.pdf ./ch06.pdf ./ch07.pdf ./ch08.pdf ./ch09.pdf ./ch10.pdf ./ch11.pdf ./ch12.pdf ./appA.pdf ./appB.pdf ./appC.pdf ./index.pdf ./ato.pdf cat output "./GNU Make 第3版.pdf" (4)
$ pdfinfo ./GNU\ Make\ 第3版.pdf
Creator:        pdftk-java 3.1.1
Producer:       itext-paulo-155 (itextpdf.sf.net-lowagie.com)
CreationDate:   Tue Jan 26 07:56:56 2021 JST
ModDate:        Tue Jan 26 07:56:56 2021 JST
Tagged:         no
UserProperties: no
Suspects:       no
Form:           none
JavaScript:     no
Pages:          298
Encrypted:      no
Page size:      516 x 660 pts
Page rot:       0
File size:      20356655 bytes
Optimized:      no
PDF version:    1.6
$ rm ./hyoushi.pdf ./mae.pdf ./maegaki.pdf ./contents.pdf ./ch01.pdf ./ch02.pdf ./ch03.pdf ./ch04.pdf ./ch05.pdf ./ch06.pdf ./ch07.pdf ./ch08.pdf ./ch09.pdf ./ch10.pdf ./ch11.pdf ./ch12.pdf ./appA.pdf ./appB.pdf ./appC.pdf ./index.pdf ./ato.pdf

$ dpkg-query -W pdftk imagemagick wget w3m
imagemagick     8:6.9.11.58+dfsg-1
pdftk   2.02-5+b1
w3m     0.5.3+git20210102-2
wget    1.21-1+b1
$ lsb_release -dr
Description:    Debian GNU/Linux bullseye/sid
Release:        unstable
$ uname -m
x86_64