10 Comandos Linux que talvez nunca ouviu falar

Linux, a powerhouse of flexibility and control, often reveals its true magic through the command line. While  ls ,  grep , and  cd  are universally known, the operating system houses a constellation of lesser-known utilities—each with unique capabilities. These obscure commands, once discovered, can enhance your workflows, increase productivity, and turn you into a command-line artisan. 

 1.  look  — Fast Dictionary Lookup 

 The  look  command performs a binary search on a sorted file, typically a dictionary, and prints all lines that begin with a given string. It's perfect for autocomplete tools, word games, or when verifying the existence of a term. 

 look pro 

 This will return all dictionary entries beginning with “pro.” Fast, lean, and astonishingly handy. 

 2.  rev  — Reverse the Characters of a Line 

 A surprisingly effective tool,  rev  reverses each line of input character by character. It might sound like a novelty, but it’s invaluable in scenarios involving cryptic text transformations or palindromic algorithms. 

 echo "Linux" | rev 

 This returns “xuniL”. Simple, elegant, and precise. 

 3.  tac  — The Reverse of  cat 

 While  cat  displays file content from top to bottom,  tac  (cat spelled backward) prints lines in reverse order. For tail-heavy logs, or when parsing data from the bottom up,  tac  can be a lifesaver. 

 tac access.log 

 This allows you to read logs in a reverse chronological sequence without needing  tail -r . 

 4.  yes  — Repetitive Stream Generator 

 The  yes  command outputs a string repeatedly until interrupted. When automating scripts or testing buffer behavior, this tool shines. 

 yes | sudo apt install mypackage 

 This command auto-confirms every prompt, useful in scripted installs. 

 5.  nl  — Number Lines of Files 

 A more sophisticated cousin of  cat -n , the  nl  command adds line numbers with robust formatting control. 

 nl file.txt 

 With support for logical page delimiters and line numbering styles,  nl  is ideal for structured file documentation. 

 6.  column  — Format Output into Columns 

 column  transforms textual data into well-aligned columns, making output dramatically more readable—especially when viewing CSVs or tabular data. 

 cat data.txt | column -t -s, 

 This aligns comma-separated data neatly into tabular format. 

 7.  shuf  — Shuffle Lines Randomly 

 Need to randomize a playlist or test against unpredictable data?  shuf  randomizes input line order effortlessly. 

 shuf list.txt 

 It’s also useful in shell-based gaming, simulation, and statistical sampling. 

 8.  comm  — Compare Two Sorted Files Line by Line 

 comm  is an unsung hero in file comparison. It contrasts two sorted files line-by-line and categorizes them: lines unique to file1, file2, and lines common to both. 

 comm file1.txt file2.txt 

 Ideal for syncing datasets or identifying deltas. 

 9.  chrt  — Manipulate Real-Time Scheduling Policies 

 For those tinkering with performance tuning,  chrt  adjusts a process’s real-time scheduling policy. Combined with  ps  or  top , it’s a potent performance tool. 

 sudo chrt -f 99 ./my_program 

 This elevates your process to the highest fixed-priority level. 

 10.  watch  — Execute a Program Periodically 

 Observe command output in near real-time with  watch . It’s perfect for monitoring resource usage, service health, or file changes. 

 watch -n 2 df -h 

 This runs  df -h  every 2 seconds, refreshing the terminal view dynamically. 

 Mastering Linux means going beyond the commonplace. These ten underutilized commands unlock new layers of potential, allowing developers, admins, and enthusiasts to operate with greater fluency and finesse. With just a bit of curiosity, even the most obscure tool can become an indispensable ally in your command-line journey.