Linux command line tool to find specific programs

command linedocumentationman

Can you please indicate me how do you find programs in the terminal without knowing the exact name?

As far as I remember, there was a command line tool that helps the user to find out other programs / command line tools associated to some key words. For example I am logged in an unknown system and I want to open a pdf, I don't know what pdf reader is installed and hence cannot open the pdf from the command line. I thought there was a command line tool that I can call with some keyword, say "pdf" and it shows me for example 7 programs that are in some way associated with "pdf", say mupdf, etc.

Or how do you do when you don't know the system you're working on or if you forgot what you installed?

I searched on google but always landed on something like How to find application's path from command line? which is not what I am asking.

Thanks

Best Answer

I think about apropos:

From man:

apropos - search the manual page names and descriptions

Example:

$ apropos pdf
dvipdf (1)           - Convert TeX DVI file to PDF using ghostscript and dvips
evince-thumbnailer (1) - create png thumbnails from PostScript and PDF documents
fix-qdf (1)          - repair PDF files in QDF form after editing
ghostscript (1)      - Ghostscript (PostScript and PDF language interpreter and previewer)
gs (1)               - Ghostscript (PostScript and PDF language interpreter and previewer)
gsnd (1)             - Run ghostscript (PostScript and PDF engine) without display
pdf2dsc (1)          - generate a PostScript page list of a PDF document
pdf2ps (1)           - Ghostscript PDF to PostScript translator
pdfdetach (1)        - Portable Document Format (PDF) document embedded file extractor (version 3.03)
pdffonts (1)         - Portable Document Format (PDF) font analyzer (version 3.03)
pdfimages (1)        - Portable Document Format (PDF) image extractor (version 3.03)
pdfinfo (1)          - Portable Document Format (PDF) document information extractor (version 3.03)
pdfseparate (1)      - Portable Document Format (PDF) page extractor
pdftocairo (1)       - Portable Document Format (PDF) to PNG/JPEG/TIFF/PDF/PS/EPS/SVG using cairo
pdftohtml (1)        - program to convert PDF files into HTML, XML and PNG images
pdftoppm (1)         - Portable Document Format (PDF) to Portable Pixmap (PPM) converter (version 3.03)
pdftops (1)          - Portable Document Format (PDF) to PostScript converter (version 3.03)
pdftotext (1)        - Portable Document Format (PDF) to text converter (version 3.03)
pdfunite (1)         - Portable Document Format (PDF) page merger
ps2ascii (1)         - Ghostscript translator from PostScript or PDF to ASCII
ps2pdf (1)           - Convert PostScript to PDF using ghostscript
ps2pdf12 (1)         - Convert PostScript to PDF 1.2 (Acrobat 3-and-later compatible) using ghostscript
ps2pdf13 (1)         - Convert PostScript to PDF 1.3 (Acrobat 4-and-later compatible) using ghostscript
ps2pdf14 (1)         - Convert PostScript to PDF 1.4 (Acrobat 5-and-later compatible) using ghostscript
ps2pdfwr (1)         - Convert PostScript to PDF without specifying CompatibilityLevel, using ghostscript
qpdf (1)             - PDF transformation software
snmpdf (1)           - display disk space usage on a network entity via SNMP

Related Solutions

Modifying PDF files

I use pdftk mainly. But here are some others to consider:

pdfsam (PDF Split and Merge): "pdfsam is an open source tool (GPL license) designed to handle pdf files"

PDFJam "A small collection of shell scripts which provide a simple interface to much of the functionality of the excellent pdfpages PDF file package (by Andreas Matthias) for pdfLaTeX." (You can also use pdfLaTeX directly.)

jPDFTweak: "jPDF Tweak is a Java Swing application that can combine, split, rotate, reorder, watermark, encrypt, sign, and otherwise tweak PDF files."

Inkscape: is a vector graphics editor that can both import PDF pages into its native SVG format, and also export as PDF.

Calibre: Open source ebook management software that can convert PDFs to other formats, and manipulate them in other ways. Comes with command line tools such as pdfmanipulate which can be useful.

Ghostscript of course can do a lot of things with PDF files too.

Command line tool for easy multiline regex search and replace

I'm not sure why Perl isn't acceptable here. On the inputs you provided, this line gives the output you asked for:

perl -0777p -e 's/.* > (.*) joined the channel\.\n(((?!.* \1 (was kicked from channel\.|was banned from channel\.)\n).*\n)+?.*\1 disconnected)/\2/mg' irc.txt

The -e argument is exactly the first argument to your magicregextool except that I added the /mg regex modifier. This may not be "unmodified" but it doesn't seem unreasonable either. If you don't want to type in the whole line, how about this script as magicregextool:

#!/usr/bin/perl -0777p
BEGIN { $::arg = shift @ARGV; }
eval $arg;

Or even:

#!/bin/sh
perl -0777pe $*

Then you just type:

magicregextool 's/.* > (.*) joined the channel\.\n(((?!.* \1 (was kicked from channel\.|was banned from channel\.)\n).*\n)+?.*\1 disconnected)/\2/mg' irc.txt

Which is the same as your sample (again other than adding the /mg modifier).

An additional benefit to this is that if you are running multiple related search/replace operations on each file, you can put them together in the same script:

#!/usr/bin/perl -0777p
s/.* > (.*) joined the channel\.\n(((?!.* \1 (was kicked from channel\.|was banned from channel\.)\n).*\n)+?.*\1 disconnected)/\2/mg;
s/(some other\n)matched text/\1/mg;

Best Answer

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Modifying PDF files

Command line tool for easy multiline regex search and replace

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