php uses Xpdf to read the content in PDF

[root@localhost ~]# mkdir -p /lcf/upan
[root@localhost ~]# mkdir -p /lcf/cdrom
[root@localhost ~]# mkdir -p /lcf/xpdf
 [root@localhost ~]# cd /lcf/upan/
[root@localhost upan]# cp xpdf/* ../xpdf/ (The downloaded file is placed in the /lcf/xpdf directory)
[root@localhost upan]# cd ../xpdf/
[root@localhost xpdf]# tar -zxvf xpdfbin-linux-3.03.tar.gz
[root@localhost xpdf]# cd xpdfbin-linux-3.03
[root@localhost xpdfbin-linux-3.03 ]# cat INSTALL
[root@localhost xpdfbin-linux-3.03]# cd bin32/
[root@localhost bin32]# cp ./* /usr/local/bin/
[root@localhost bin32]# cd ../ doc/
[root@localhost doc]# mkdir -p /usr/local/man/man1
[root@localhost doc]# mkdir -p /usr/local/man/man5
[root@localhost doc]# cp * .1 /usr/local/man/man1
[root@localhost doc]# cp *.5 /usr/local/man/man5

If you don’t need to read Chinese, you can go here It's over, if necessary, let's continue

[root@localhost doc]# cp sample-xpdfrc /usr/local/etc/xpdfrc
[root@localhost xpdf]# cd /lcf/xpdf
[root@localhost xpdf]# tar -zxvf xpdf -chinese-simplified.tar.gz
[root@localhost xpdf]# cd xpdf-chinese-simplified
[root@localhost xpdf]# mkdir -p/usr/local/share/xpdf/chinese-simplified
[root@localhost xpdf]# cd xpdf-chinese-simplified/
[root@localhost xpdf-chinese-simplified]# cp Adobe-GB1.cidToUnicode ISO-2022-CN.unicodeMap EUC-CN.unicodeMap GBK.unicodeMap CMAP /usr/local/share /xpdf/chinese-simplified/

Copy the contents of the file add-to-xpdfrc in chinese-simplified to the /usr/local/etc/xpdfrc file. Remember that the path inside must be correct. (Note that the Simplified Chinese package here includes the following three formats: ISO-2022-CN, EUC-CN, GBK. Please see clearly, UTF-8 is not supported. You can convert to GBK first and then escape)

3. Function implementation At this point, all the configuration is complete, and we are going to start using it. If it is a simple PDF reading, then just use the following statement. $content = shell_exec('/usr/local/bin/pdftotext '.$filename.' -'); If you need to convert to Chinese, add parameters like this. $content = shell_exec('/usr/local/bin/pdftotext -layout -enc GBK '.$filename.' -'); Of course, adding parameters will still not affect the English conversion, so feel free to use it. It should be noted that what is transferred here is GBK encoded. Many websites now use UTF-8. If you want to avoid displaying garbled characters, you need to escape it again. $content = mb_convert_encoding($content, 'UTF-8','GBK'); The read content can be processed by yourself by writing code. Main parameters of pdftotext: OPTIONS Many of the following options can be set with configuration file com- mands. These are listed in square brackets with the description of the corresponding command line option. -f number Specifies the first page to convert. -l number Specifies the last page to convert. -layout Maintain (as best as possible) the original physical layout of the text. The default is to 'undo' physical layout (columns, hyphenation, etc.) and output the text in reading order. -fixed number Assume fixed-pitch (or tabular) text, with the specified charac- ter width (in points). This forces physical layout mode. -raw Keep the text in content stream order. This is a hack which often "undoes" column formatting, etc. Use of raw mode is no longer recommended. -htmlmeta Generate a simple HTML file, including the meta information. This simply wraps the text in

 and 

and prepends the meta headers. -enc encoding-name