Unix / Linux Commands #5: grep and find, Search Text and Files Like a Pro

Code & Test Automation |    / @codetestautomation   Search like a pro in a real bash terminal with real output: grep to find text inside files and find to locate files by name, type, size and age. Covers grep -i, -n, -w, -v, -c, -l, -L, -E, context with -A -B -C, recursive grep -rn with --include and --exclude-dir, and find -name, -iname, -type, -maxdepth, -size, -mtime and -exec, plus combining find with grep and the macOS / BSD differences. In this video: grep basics, case sensitivity, exit status 0, 1 and 2 grep -n, context lines, -w, --color, -v, -c, -E with alternatives, ^ and $ grep on several files, -l and -L, grep -r and -rn, --include, --exclude-dir, Ctrl+R history search find -name with quotes, -iname, -type f and d, -maxdepth find -size, -exec, -mtime and -newermt, find + grep, safe use of -delete macOS / BSD grep and find differences Video 5 of 10 in the Unix / Linux Commands series, for freshers and experienced engineers on Linux, macOS and most Unix systems: navigation, file operations, viewing and searching files, permissions, pipes and redirection, processes, disk tools and daily workflows. Almost every minute is a real terminal session with real output. CHAPTERS 0:00 Introduction 1:07 grep: search inside a file 1:27 grep -c: count matches 1:49 grep is case sensitive 2:14 grep -i: ignore case 2:32 grep -n: line numbers 2:50 grep with context 3:13 grep -w: whole words 3:36 Highlighting matches 3:56 grep -v: invert the match 4:14 grep -v with -c 4:34 Several patterns with -E 5:00 Anchors: start and end of line 5:24 grep on several files 5:43 grep -l: list files only 6:02 When the file does not exist 6:28 grep -r: search a whole folder 6:49 grep -rn: path and line number 7:06 Limit the search to some files 7:29 TODO or FIXME, and -rl 7:48 History: find that grep again 8:06 macOS and BSD grep 8:29 find: files by name 8:53 Quote the pattern 9:19 find -type f and -type d 9:41 Where to start 10:06 find -size: big files 10:32 find -exec: act on each result 10:55 find -mtime: by age 11:36 Combining find and grep 12:18 Delete safely with find 12:39 macOS and BSD find 13:03 grep or find: which one? 13:24 Recap 14:45 Next episode HOW THE DEMOS WERE MADE Everything between the title card and the recap is a live screen recording of a real bash 5.2 shell in xfce4-terminal on Debian Linux (GNU coreutils 9.7). Every command was typed at a human pace and every line of output is the real output; nothing was edited in afterwards. The shell runs in a private practice sandbox: an unprivileged Linux user, mount and PID namespace whose home folder, /home/learner, holds only the practice files created by the mklab.sh script in the project zip, and whose host name is unix-lab. No sudo was used, and no command touched anything outside the practice folder. This minimal machine has no man-db, so the man command here is a small wrapper that shows the official GNU manual pages with mandoc and the real less pager. Keys pressed in the terminal appear in on-screen badges with the macOS Terminal keys and the Linux keys. When macOS or BSD tools use different options, the macOS form is shown as TYPED ONLY: typed on screen, never run, and cancelled with Ctrl+C, so no output is ever invented. CORRECTIONS TO THE COURSE NOTES grep -r: GNU grep searches the current folder when no path is given, but BSD grep on macOS warns about reading standard input, so always pass the folder (grep -r TODO .). find . -size +10M: GNU find rounds sizes up to whole units (MiB here), so -size -1M matches only empty files; use -size -1024k for 'smaller than 1 MiB'. find -mtime counts whole 24-hour days and drops the fraction: -mtime -7 is 'less than 7 days ago', and -mtime +30 means at least 31 full days old. GNU find has -newermt DATE for an exact date. BSD find (macOS) requires the starting folder: find -name x fails there; always write find . -name x. Quote the pattern ('*.txt') so the shell does not expand it first. egrep is obsolete (GNU grep 3.8+ warns); use grep -E 'a|b'. No output from grep is not an error: exit status 1 means no match, 2 means an error. PRACTICE 1. cd projects and run grep -rn TODO . then add --include='*.java'. 2. grep -v INFO logs/app.log | head and grep -c ERROR logs/*.log. 3. find . -name '*.java' and find . -size +10M. 4. find logs -mtime +30 (list only; never add -delete before reading the list). Practice tip: open a terminal on Linux, macOS or WSL, make a practice folder, and type every command right after you see it. The recording is a real bash 5.2 session on Debian Linux with GNU coreutils; when macOS or BSD tools behave differently, the video shows the macOS form as TYPED ONLY (not run) and says so. Next video: #06 Permissions: chmod, chown and ls -l. #Linux #Unix #Bash #LinuxCommands #CodeAndTestAutomation Subscribe to Code & Test Automation for more Linux, Java, coding and test automation tutorials:    / @codetestautomation