Batch script for all files in folder

[inka]

Greetings!
I would like to ask for you help resolving a little problem. Unfortunately I`m not a programmer

I have a lot of pdf files and I want to convert them to a lower quality for the web. I tried to use the following command (using ghostscript):

gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/default -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf input.pdf

Is there a way to make a batch to do this for all pdf-s in a folder?

Thank you in advance for your help!
I.

ps. if anyone knows a better way to reduce pdf dpi you can tell that too

[hazel]

for name in *.pdf ; do command ; done.

You will have to use "$name" in your command string instead of the literal filename.

[inka]

Thank you for your answer!
But could you please a little more specific what do I have to do?

Write the line :
for $name in *.pdf ; do command ; done.
in a file and run it?

Thank you for your patiance!

[Cabhan]

The command that hazel gave is basically a loop in a Bash script. If we wrote a script to do it, it would look like this:

for file in *.pdf; do
    output_file=$(echo "$file" | sed -re 's/\.pdf$/out.pdf/')

    gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/default -dNOPAUSE -dQUIET -dBATCH -sOutputFile="$output_file" "$file"
done

What this script does is:

For every file ending in '.pdf' in the current directory, create a string called output_file, and then run the command, substituting the input file for "$file", and the output file for "$output_file". The output file name that I created here just adds '.out' before the '.pdf' of the filename. So we go from "file.pdf" to "file.out.pdf".

Hazel's approach was to collapse this script into a single line so that it's easy to run:

for file in *.pdf; do output_file=$(echo "$file" | sed -re 's/\.pdf$/out.pdf/'); gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/default -dNOPAUSE -dQUIET -dBATCH -sOutputFile="$output_file" "$file"; done

You could also copy the script that I wrote above into a file, and be able to run, for instance, a "downgrade_all_pdfs" command to run the command automatically in the current directory.

This is all about Bash scripting. If you want to learn more, you can check:
Bash Guide for Beginners

Advanced Bash-Scripting Guide

[inka]

Thank you very much for your answer!