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🖥️ Bash Opreators
A quick reference guide to essential bash command operators and their usage.
> — Write to File (Overwrite)
This operator creates a new file or overwrites the contents of an existing file.
echo "Hi" > file1
📄 Creates file1 and writes "Hi" into it. If file1 already exists, its content is replaced.
>> — Append to File
Adds content to the end of an existing file without deleting what's already there.
echo "Hi" >> file1
📝 Appends "Hi" to the end of file1.
&& — AND Operator
Runs the second command only if the first succeeds.
apt update && apt upgrade
🔗 apt upgrade runs only if apt update completes successfully.
; — Run Multiple Commands
Executes commands sequentially, regardless of success or failure.
echo "Hi" > file1 ; cat file1
🔄 Both commands are executed one after the other.
* — Wildcard (All Matching Files)
Matches all files that meet the pattern.
cat file*
🌐 Displays the contents of all files starting with file.
[ ... ] — Specific Character Matching
Reads files that match specific characters at the position defined in brackets.
cat file[1,2,3]
📚 Reads file1, file2, and file3 (if they exist). Equivalent to:
cat file1 file2 file3