# Getting Help

Every command can explain itself, with --help for a short list of its options and man for its full manual page, type and which tell you what kind of command a name is, and an error message says what went wrong when you read it one part at a time.

Apprentice · Unix · Linux · Updated November 10, 2026

## After this lesson you can

- Find out what a command and its options do with --help and man
- Tell a shell builtin from a program with type and which
- Read an error message to find the command, the name and the problem it reports

## Key takeaways

- A command followed by --help prints a short list of its options. In the usage line, [ ] means optional and ... means you can give more than one.
- man and a command's name opens its manual page, in the same viewer as less. / searches it and q quits.
- type says whether a name is built into the shell, an alias or a program file. which prints a program file's path, and nothing for a builtin.
- An error names who is speaking, what it was working on and what went wrong. The name in it is usually the clue.

A tutorial says "count the lines with `wc -l CHANGELOG.md`", and you've never seen `wc`. Or the terminal answers a command with an error that looks like a scolding. You could search the web, but the manual for the exact version you have is already on your computer, and an error usually says what went wrong, once you know how to read it.

The examples use the practice folder from *Reading Files: cat and less*: `cd ~/terminal-practice/recipe-box`.

## --help: the short version

Most commands print a short guide to themselves when you add `--help` (read "dash dash help"):

```bash
wc --help
```

```text
Print newline, word, and byte counts for each FILE, and a total line if more
than one FILE is specified.

Usage: wc [OPTION]... [FILE]...

Arguments:
  [files]...

Options:
  -c, --bytes            print the byte counts
  -m, --chars            print the character counts
      --files0-from <F>  read input from the files specified by
                         NUL-terminated names in file F;
                         If F is - then read names from standard input
  -l, --lines            print the newline counts
  -L, --max-line-length  print the length of the longest line
      --total <WHEN>     when to print a line with total counts;
                         WHEN can be: auto, always, only, never
  -w, --words            print the word counts
  -h, --help             Print help
  -V, --version          Print version
```

`wc` stands for *word count*. Read the **usage line** like a recipe card: `wc`, then options, then files. Square brackets, `[ ]`, mean "optional", and `...` (read "and more") means you can give more than one. Each option below has a short and a long name for the same thing: `-l` and `--lines` both count lines. Try the one the tutorial wanted:

```bash
wc -l CHANGELOG.md
```

```text
94 CHANGELOG.md
```

## man: the full manual

`--help` is the short version. The full one is the command's **manual page**, opened with `man` (short for *manual*):

```bash
man wc
```

```text
WC(1)                       General Commands Manual                       WC(1)

NAME
       wc  -  Print  newline,  word, and byte counts for each FILE, and a total
       line if more than one FILE is specified.

SYNOPSIS
       wc    [-c|--bytes]     [-m|--chars]     [--files0-from]     [-l|--lines]
       [-L|--max-line-length] [--total] [-w|--words] [-h|--help] [-V|--version]
       [files]

DESCRIPTION
       Print  newline, word, and byte counts for each FILE, and a total line if
       more than one FILE is specified.

 Manual page wc(1) line 1 (press h for help or q to quit)
```

Every manual page has the same parts: **NAME** says what the command does in one line, **SYNOPSIS** shows how to type it (`|`, read "or", separates two ways of writing one option), **DESCRIPTION** explains, and **OPTIONS** lists each option. The page opens in the same viewer as `less`, so the keys are the ones you know: Space, b, the arrows, and **q** to quit. To find one option, search for it with a comma after it: type `/-l,` and press Enter. The page jumps to the line `-l, --lines`, with `print the newline counts` under it.

Pages are worded differently on a Mac and on some Linux systems, but they all have these parts. On a Mac, many commands don't understand `--help`, so use `man` there.

## type and which: what kind of command is it?

Try `man cd`, and Ubuntu answers `No manual entry for cd` (a Mac opens one page about every builtin). That's because `cd` isn't a program on your disk: it's part of bash itself, a **shell builtin**. `type` tells you what any command name really is:

```bash
type cd
type ls
type wc
```

```text
cd is a shell builtin
ls is aliased to `ls --color=auto'
wc is /usr/bin/wc
```

Three kinds of answer. `cd` is built into the shell, and `help cd` explains it. `ls` is an **alias**, a short name for a longer command (here, `ls` with colors; Module 4 shows how to make your own). `wc` is a program file, at the path shown. (If you've already run `wc` in this terminal, it says `wc is hashed (/usr/bin/wc)`: bash remembers where it found it.) `which` finds only program files:

```bash
which wc
which cd
```

```text
/usr/bin/wc
```

`which cd` printed nothing: there's no file to find. In zsh on a Mac, `which cd` says `cd: shell built-in command` instead.

## Reading an error message calmly

An error isn't the terminal being cross with you. It's a report, and most follow a pattern: **who** is speaking, **what** it was working on, and **what went wrong**, separated by colons:

```bash
cat CHANGELOG
cd recipes
```

```text
cat: CHANGELOG: No such file or directory
bash: cd: recipes: No such file or directory
```

![The error "cat: CHANGELOG: No such file or directory" with its three parts labeled: cat is who is speaking, CHANGELOG is the name it was working on, and No such file or directory is what went wrong](https://fsdtrainingmedia.blob.core.windows.net/public/images/2026/11/2343bb90a843499898d61366f8f83f8b.webp)

`cat` couldn't find a file called `CHANGELOG`: the real name ends in `.md`. In the second line bash is speaking about its builtin `cd`, and there's no `recipes` folder here. The name in the middle is the clue: check its spelling, and check you're in the right folder with `pwd` and `ls`.

A misspelled command gets a longer answer on Ubuntu:

```bash
claer
```

```text
Command 'claer' not found, did you mean:
  command 'clear' from deb ncurses-bin (6.6+20251231-1)
Try: sudo apt install <deb name>
```

The word that matters is `'claer'`, a typo. The advice to install something is for a program you really don't have; `clear` is already there, so fix the spelling instead. (In zsh it's `zsh: command not found: claer`.) An option that doesn't exist gets `unexpected argument` or `invalid option`, and the cure is the command's `--help`.

## Check yourself

2 questions to try on the lesson page.

## So what

`--help`, `man`, `type` and a calm read of the error answer most "what does this do?" and "why didn't that work?" questions in seconds, right in the terminal, for commands you've never seen before.

## Key terms

- [man](https://www.ask-codey.com/glossary/man)
- [Shell Builtin](https://www.ask-codey.com/glossary/shell-builtin)
- [which](https://www.ask-codey.com/glossary/which)
- [wc](https://www.ask-codey.com/glossary/wc)
- [alias](https://www.ask-codey.com/glossary/alias-unix)

## Cheat sheets

- [Getting Help](https://www.ask-codey.com/cheat-sheets/bash-getting-help-cheat-sheet)

## Related

- [Reading Files: cat and less](https://www.ask-codey.com/lessons/bash-reading-files)
- [Your Command History](https://www.ask-codey.com/lessons/bash-command-history)

Source: https://www.ask-codey.com/lessons/bash-getting-help