Terminal Tips

Text search in files

$ grep -rnI {word} {directory}

# Examples
$ grep -rnI origin .
$ grep -rnI foo apps/bar/

Open a text editor on a particular line

$ vim {file} +{line}

# Examples
# Can be used in other text editors.
$ vim arquivo.py +136

Execute a process in the background.

$ {process} &

# Example
$ ./start.sh &

Run background processes resistant to hangup signals

If we only use &, when we disconnect from the terminal a hangup signal is sent, stopping all processes bound to it.

$ nohup {./process} &

# Example
$ nohup python script.py >> output.txt 2 >> error.txt &

Logs (outputs and errors) are generated automatically and we can manipulate their respective directories as in the example. When we use “>” the log file is replaced every time a new log is issued when we use “>>” when a new log is issued it is saved to the end of the file, like an append.

Make one command be processed by another (pipe connection)

$ {first_command} | {second_command}

# Example
# Displays processes that contain the word python
$ ps aux | grep python

Command chaining

When we use && the second_command is only executed if first_command was executed successfully.

{first_command} && {second_command}
{first_command} ; {second_command}

Creating custom shortcuts

$ alias {shortcut_name}="{command}"

# Example
$ alias migrate="python manage.py migrate"
$ migrate
Operations to perform:
  Apply all migrations: ...

Capture range of lines in text files

# Get the first three lines of text-file.txt
$ sed -n '1,3p' text-file.txt

# we can go ahead and create a new file from the result
$ sed -n '1,3p' text-file.txt >> text-file-slice.txt

Keyboard shortcuts

control+A: Go to the beginning of the line.

control+E: Go to the end of the line.

control+D: Deletes the selected character.

control+W: Cut the word before the cursor.

control+U: Cut the line before the cursor.

control+Y: Paste the last things cut out.

control+R: Search in command history.

tab: Autocomplete