Download to read offline
![20
Finding files
• ‘grep’ – this is the command when you want to search the contents of
a file
• General form is ‘grep OPTIONS “search string” file_name_wildcarded’
• Common OPTIONS
• -v (invert match – show lines that don’t match)
• -i (case insensitive search)
• -H (show file names)
• -n (show line number)
• -r (recurse through subdirectories)
• “search string” includes regular expressions
• Entire books have been written to explain regular expressions!
• ^ (beginning of line)
• $ (end of line)
• . (any single character)
• [ABCabc] (single character that matches any of A, B, C, a, b, c)](https://image.slidesharecdn.com/20250409linuxrpi-250412002843-5a31af83/85/Introduction-to-Linux-with-Focus-on-Raspberry-Pi-20-320.jpg)
![20
Finding files
• ‘grep’ – this is the command when you want to search the contents of
a file
• General form is ‘grep OPTIONS “search string” file_name_wildcarded’
• Common OPTIONS
• -v (invert match – show lines that don’t match)
• -i (case insensitive search)
• -H (show file names)
• -n (show line number)
• -r (recurse through subdirectories)
• “search string” includes regular expressions
• Entire books have been written to explain regular expressions!
• ^ (beginning of line)
• $ (end of line)
• . (any single character)
• [ABCabc] (single character that matches any of A, B, C, a, b, c)](https://image.slidesharecdn.com/20250409linuxrpi-250412002843-5a31af83/75/Introduction-to-Linux-with-Focus-on-Raspberry-Pi-20-2048.jpg)
Uploaded byDavid Horvath
Introduction to Linux with Focus on Raspberry Pi
Presented at Phil-Mont Mobile Radio Club April 2025 Meeting
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Introduction to Linux with Focus on Raspberry Pi
- 1. Introduction to Linuxwith Focus on RPI David B. Horvath, CCP, MS, KB3RIJ The Phil-Mont Mobile Radio Club Giant Supermarket, Willow Grove, PA April 9, 2025
- 2. 2 Contact Information The Authorcan be contacted at: 504 Longbotham Drive, Aston PA 19014-2502, USA Phone: 1-610-859-8826 Email: dhorvath@cobs.com Web: http://www.cobs.com/ LinkedIn: http://www.linkedin.com/in/dbhorvath All trademarks and servicemarks are the property of their respective owners. Copyright © 2025, David B. Horvath, CCP — All Rights Reserved
- 3. 3 My Background • Davidis an IT Professional who has worked with various platforms since the 1980’s with a variety of development and analysis tools. • He has presented at various conferences, workshops and seminars in Australia, France, the US, Canada, and even Oxford England (about the British Author Nevil Shute). • He holds an undergraduate degree in Computer and Information Sciences from Temple University, a Masters in Organizational Dynamics from UPENN, and recently completed a Masters in Data Sciences. • Most of his career has been in consulting (although he has been in- house most of this century) in the Philadelphia PA area. He is currently in Data Analytics "Engineering" at a Regional Bank. • He has several books to his credit (none Ham related) and is an Adjunct Instructor covering IT topics. • Third Class Radio Telephone ca 1978 operating on WHHS • General Amateur 2008 but didn’t really get active until 2020
- 4. 4 Abstract • History ofRaspberry PI • History of UNIX and Linux • Backing up and Moving Files to/from the Raspberry PI • Basic file and directory actions • Moving files to/from Raspberry PI • Remote access to Raspbery PI • Important directories and devices • Updating your applications, tools, and operating system
- 5. 5 History of RaspberryPI • Initial Prototype in 2006 • Project in 2012 to help school children learn about computers • BBC Micro by Acorn Computers was under $850 (2025 USD) • Making the RPI greater than an order of Magnitude cheaper • Tend to be less powerful than home PC and many mobile devices • Boots and runs off SD chip • USB Ports along with (varies) Ethernet, WiFi, Bluetooth, HDMI, audio • GPIO Header hardware interfaces allowing PWM, binary, A/D) • Video, keyboard, and mouse can be “headless” • Low Power Consumption (fed via USB port, AC or battery) • Runs Linux, BSD, Android, limited MS Windows, etc.!
- 6. 6 History of UNIXand Linux • What is Linux? • How is it pronounced? • Lynn-icks • Line-icks • Lean-icks • What is it? • An operating system like UNIX • Can be Free • User Supported • Includes GNU • Has no commercially copyrighted code • Versions are know as “Distros” (Distributions)
- 7. 7 History of UNIXand Linux • What is Linux? • Linux is really the “kernel” • What is GNU? • “GNU is Not UNIX” — replicates UNIX tools and utilities • Free Software Foundation • Governed by “copyleft” (GPL) instead of “copyright” • Why would you want Linux? • Freely available and easily modifiable • More efficient that Microsoft’s Windows • Is not Microsoft’s • Looks and Feels like UNIX • The fun of exploration (is also “sexy”) • Robust • It is a “Flavor” of UNIX
- 8. 8 History of UNIXand Linux • What is UNIX? • UNIX is a character-based server oriented operating system • Originally developed at AT&T Bell Labs • Was an internal project never intended for commercial sale • Originally given away for free! But is now commercial • The word “UNIX” is trademarked • Is a specific operating system • Is a generic term • “Flavors” include AIX, Z/OS, SunOS/Solaris, HP-UX,, Linux, BSD, Apple Mac OS, and others. • Most replaced by Linux now
- 9. 9 History of UNIXand Linux • What is UNIX? • UNIX is a programmers’ environment • Is very flexible, extensible, and consists of many small tools that are readily combined. WGPCGR • Gained popularity in colleges (who got it free from AT&T) • Grew from user support (notice a trend?) • Available on just about every computer system made today! • Very transportable skill
- 10. 10 Backing up andMoving Files to/from the Raspberry PI • There are several main methods • Full system (back up the SD chip): https://sourceforge.net/projects/win32diskimager/files/Archive/Win32DiskI mager-0.9.5-install.exe/download • Win32DiskImager-0.9.5-install.exe • Included with Allstar distribution • Allows you to read/write entire chip (all filesystems)
- 11. 11 Backing up andMoving Files to/from the Raspberry PI • There are several main methods (continued) • Within the Application
- 12. 12 Backing up andMoving Files to/from the Raspberry PI • There are several main methods (continued) • Individual Files: sftp to your PC – MobaXterm or Windows or …
- 13. 13 Backing up andMoving Files to/from the Raspberry PI • There are several main methods (continued) • Blocks of Files: tar, zip, sftp to your PC • ‘gzip -c /var/log/*log > zippedlogs’ • ‘tar -cvf tarlogs /var/log/*log’ • Thumb Drive • Insert thumb drive • Determine where it is mounted (will usually self-mount) • ‘more /etc/fstab’ • ‘df –h’ • Create the directory and copy to it • ‘sudo mkdir xxx’ • ‘sudo cp ~/.* xxx/’ • Hybrid with USB SD card reader
- 14. 14 Basic file anddirectory actions • If you are familiar with old MS/DOS much of this will be familiar • Lots of differences though • Broken down into the following areas: • Directory Navigation • Finding Files • Manipulating Files • Space Usage and Availability • Command History (Remember: the best programmers are lazy) • System Commands • More Information • Introduction to Editing (if time allows)
- 15. 15 Directory navigation • Youwill find UNIX directory structure very familiar • Windows shares many similarities include tree-metaphor structure • Use / instead of Windows’ • No drive letters • All disks are attached to the main directory structure (“mounted”) • DOS 3.1 – 6 included the ‘join’ command Cygwin is a special case • Directory Navigation • ‘cd’ – change directory • ‘cd’ with no parameters – change to home directory • ‘cd -’ – change to previous directory (where you were before) • ‘pwd’ – display the current directory (Windows ‘cd’ does this)
- 16. 16 Directory navigation • Absolute,Relative, and Home-relative Forms • Absolute specifies the entire directory path • cd /home/dhorvath/subdirectory/subsub/etc • Relative specifies the directory path relative to the current directory • assuming current directory is /home/dhorvath • cd subdirectory/subsub/etc • cd ../dhorvath/subdirectory/subsub/etc • cd .. – takes you up one directory level, can be repeated • “.” – current directory (handy when a command needs a directory and you’re already there)
- 17. 17 Directory navigation • Absolute,Relative, and Home-relative Forms • You can also specify via the home directory • cd ~/subdirectory/subsub/etc – relative to my home directory • cd ~userid/subdirectory/etc – relative to userid’s home directory • Directory forms can be used with any command (not just ‘cd’). • Remember that case matters • Enclose path in “” if it contains special characters or spaces • Can cheat and use wild cards if you’re lazy
- 18. 18 Finding files • ‘ls’is the primary command for looking at files • Many options are available • -a – show all files; by default, files that begin with “.” are “hidden” • -l – long display showing full information • -1 – list in one column • -t – sort by time • -r – reversed (used with -t) • -R – recurse through subdirectories • Watch for “Arg list too long” – your wildcard list got too large • Windows requires individual programs to expand wildcards • UNIX shell expands wildcards “on the command line”
- 19. 19 Finding files • ‘find’is much more complex than ls with many more features • Too many to cover here! • Form is ‘find DIRECTORY –name “wildcard*string” ACTION • DIRECTORY is where to search (and all subdirectories) • -name “wildcard*string” – files to search for • ACTION is one of many options including –print, -ls, and –exec • One use is to get around “Arg list too long” error • Often used to find a specific file if you have no idea where it is • Can execute specific commands on each file found
- 20. 20 Finding files • ‘grep’– this is the command when you want to search the contents of a file • General form is ‘grep OPTIONS “search string” file_name_wildcarded’ • Common OPTIONS • -v (invert match – show lines that don’t match) • -i (case insensitive search) • -H (show file names) • -n (show line number) • -r (recurse through subdirectories) • “search string” includes regular expressions • Entire books have been written to explain regular expressions! • ^ (beginning of line) • $ (end of line) • . (any single character) • [ABCabc] (single character that matches any of A, B, C, a, b, c)
- 21. 21 Manipulating files • Literallyhundreds of commands • ‘cp’ – copy file contents to a new name • ‘mv’ – move file to a new directory or name • ‘cat’ – concatenate file onto another or to your screen • ‘more’, ‘less’, ‘pg’ – display contents of file one screen at a time • ‘head’ – show first 10 lines of a file • ‘tail’ – show last 10 lines of a file • ‘rm’ – remove file • ‘mkdir’ and ‘rmdir’ – create and remove directories
- 22. 22 Space Usage andAvailability • In support roles, we constantly are faced with questions about space: • “how much is used?” • “how much is left?” • ‘ls -l’ will tell you how big a specific file is -r-xr-x--- 1 dhorvath Users 324 Feb 25 2009 logging.properties dr-xr-x--- 4 dhorvath Users 16384 Aug 25 23:35 mingw • Size shown for directories is the space for the directory itself, not the files contained within • Because an individual file can have multiple directory entries (called links), you can’t just add up the sizes of the files.
- 23. 23 Space Usage andAvailability • ‘du’ will tell you how much space is used by all the files in a directory (and any subdirectories) $ du 0 ./Process/2009-01-02_bill/final 0 ./Process/2009-01-02_bill 40 ./Process/error_processed_files 0 ./Process/misc 1121952 ./Process • And is smart enough to handle linked files • You can specify the directory to determine usage
- 24. 24 Space Usage andAvailability • ‘df’ will tell you how much space is used/available in a file system • With no options, will show all file systems • ‘df .’ will show for the file system that holds the current directory $ df . Filesystem 512-blocks Free %Used Iused %Iused Mounted on /dev/fslv01 1101004800 144043800 87% 104805 1% /ingmnt/ifmdata • inode are the number of files the file system can hold • I will often use -m or -g options to get values in Megabytes or Gigabytes
- 25. 25 Korn shell andGNU Forms of History • Programmers are lazy and UNIX/Linux helps! • Many tasks are repetitive so using history helps • vi and emacs modes • Enable with ‘set -o vi’ or ‘set -o emacs’ • Modes are mutually exclusive • Allows the use of basic editor navigation and search commands • Demonstrate • “PC DOS” mode under Cygwin • Shows as emacs mode • Really behaves like the old doskey mode
- 26. 26 Korn shell andGNU Forms of History • History commands • ‘fc’ – “Fix Command” – list or recall commands • fc –s string • fc –l • ‘history’ – command history, often an alias for ‘fc -l’
- 27. 27 Editing • ‘nano’ –easy editor that was originally named “TIP is not PICO” (another easy editor) • ‘vi’ – Visual display editor is available absolutely everywhere, ‘vim’, which stands for ViIMproved is an updated version • ‘emacs’ – stands for Editor MACroS originally for TECO (Text Editor and Corrector for DEC Systems) by Richard M Stallman in 1976. Very extensible • ‘ed’ – text editor designed for print terminals • ‘sed’ – stream editor much like ‘ed’ but designed for automated manipulation. • Note the tip sheets for nano, vi/vim, and emacs
- 28.
- 29. 29 System Commands • ‘sudo’– super user do (run as administrator) • ‘sudo raspi-config’ – not available with allstar install, configures RPi
- 30. 30 System Commands • ‘sudoshutdown -h now’ – shut down system immediately • ‘sudo reboot’ – reboot the system • ‘sudo apt-get’ – APT package handling utility • top • ps –ef
- 31. 31 More Information • QuickOverview of Important Commands • ‘man’ – always your friend! • ‘command -?’ – quick summary of that command • ‘command --help’ – GNU style quick summary • Other information sources • Obviously google • RPI Magazine -- https://store.rpipress.cc/collections/latest- releases/products/raspberry-pi-official-magazine-152
- 32. 32 Remote access toRaspbery PI • Access: • Putty: • MobaXterm • Cygwin WinX Server • Windows ssh, sftp • TeamViewer
- 33. 33 Important directories anddevices • / -- root directory • /home – general directory for users • /home/YOURID • ~YOURID or just ~ • /home/MYID • ~MYID • /etc – configuration files • /usr • /usr/bin • /usr/local • /usr/local/bin • /proc – information about processor • /bin • /dev -- devices • /dev/null • /dev/YOURDEVICE
- 34. 34 Updating your applications,tools, and operating system • Several different methods • Via the Application (like Stratux) • Probably least common form • Fresh Install – new chip • Via apt-get commands under Linux • ‘sudo apt-get check’ – check on updates • ‘sudo apt-get update’ – retrieve list of available packages • ‘sudo apt-get upgrade’ – perform any necessary upgrades • Can be dangerous • ‘apt’ is a newer version of ‘apt-get’ but may not be in your distro.
- 35. 35 Wrap Up Questions and Answers ?! ?! ?!?! ? ? ? ? ! ! ! !
- 36. 36 Introduction to Linuxwith Focus on RPI The Author can be contacted at: David B. Horvath, CCP 504 Longbotham Drive, Aston PA 19014-2502, USA Phone: 1-610-859-8826 Email: dhorvath@cobs.com Web: http://www.cobs.com/ LI: http://www.linkedin.com/in/dbhorvath
- 37. 37 Introduction to Linuxwith Focus on RPI • It is all about choices
- 38. 38 References • https://raspberrytips.com/raspberry-pi-history/ • https://www.in2013dollars.com/uk/inflation/2006?amount=350 •https://www.cam.ac.uk/stories/raspberrypi • https://en.wikipedia.org/wiki/Raspberry_Pi • https://xkcd.com/378/ • https://www.cam.ac.uk/stories/raspberrypi • https://www.techspot.com/article/531-eben-upton-interview/ • https://www.geeksforgeeks.org/how-to-upgrade-raspberry-pi-os/ • GPIO PINS https://pinout.xyz/ • SPI/I2C - https://en.wikipedia.org/wiki/Serial_Peripheral_Interface https://en.wikipedia.org/wiki/I%C2%B2C • Linux Cheat sheet https://phoenixnap.com/kb/linux-commands-cheat- sheet
- 39. 39 References • https://sourceforge.net/projects/win32diskimager/files/Archive/Win32DiskI mager-0.9.5-install.exe/download • https://raspberrystreet.com/learn/how-to-backup-raspberrypi-sdcard •https://www.putty.org/ • https://mobaxterm.mobatek.net/download-home-edition.htm • https://x.cygwin.com/ • VIM cheat sheet: https://github.com/sk3pp3r/cheat-sheet- pdf/blob/master/pdf/vim-cheat-sheet.pdf • NANO Cheat Sheet https://www.nano- editor.org/dist/latest/cheatsheet.html • GNU emacs Cheat Sheet https://www.gnu.org/software/emacs/refcards/pdf/refcard.pdf
- 40. 40 Wrap Up forReal Questions and Answers ?! ?! ?! ?! ? ? ? ? ! ! ! !