What is aspell Command in Linux and Practical Examples?

The aspell command in Linux is a command-line spell-checking tool that can be used to check the spelling of one or more text files. Aspell uses a dictionary of words to determine which words are spelled correctly, and can also suggest possible corrections for misspelled words.

Installing aspell Package

To install aspell on a Linux system, you can use the package manager provided by your Linux distribution. The exact steps will vary depending on which distribution you are using, but in general, you can follow these steps:

Open a terminal window on your Linux system.

Update the package index and install aspell by running (Ubuntu and other Debian-based distributions):

apt update
apt install aspell

For Red Hat-based distributions, use

yum update
yum install aspell 

Once the installation process is complete, you can verify that aspell is installed and working by running

aspell --version

That should display the version number of the aspell program.

Using The aspell Command

To use the aspell command, you must first open a terminal window on your Linux system. From there, you can use the following commands:

• aspell check <file>: This command checks the spelling of the specified file and displays any misspelled words, along with possible corrections.
• aspell list: This command reads the input from standard input (e.g., keyboard) and displays a list of all misspelled words.
• aspell -a: This command checks the spelling of the input from standard input (e.g., keyboard) and displays the misspelled words as they are encountered, along with possible corrections.
• aspell create master <file>: This command creates a new dictionary file from the specified file, which should contain a list of words (one per line).
• aspell -d <dictionary>: This command sets the dictionary to use for spell-checking. The <dictionary> parameter should be the name of a dictionary file that has been previously created with the create command.

The aspell command also provides a number of other options that you can use to modify its behavior. For example, you can use the -l flag to specify the language to use for spell-checking, or the -p flag to specify a personal word list file that will be used in addition to the default dictionary. 

Practical Examples of The aspell Command

Here are some examples of using the aspell command in Linux:

Check The Spelling of a File and Display any Misspelled Words

To check the spelling of the "article.txt" file and display any misspelled words, you would use the following command:

aspell check article.txt

Check the Spelling of The Input From Standard Input and Display Any Misspelled Words

To check the spelling of the input from standard input and display any misspelled words, you would use the following command:

aspell list

The above won't do anything, you have to pipe it like so:

echo "The qick brwon fox jmps over the lazzy dog" | aspell list

This command will read the input from the echo command and check the spelling of each word in the input. Any misspelled words will be displayed in a list. Here is what you would get:

$ echo "The qick brwon fox jmps over the lazzy dog" | aspell list
qick
brwon
jmps
lazzy

Check the Spelling of The Input From Standard Input, Display Any Misspelled Words and Possible Corrections

To check the spelling of the input from standard input and display any misspelled words as they are encountered, you would use the following command:

echo "The qick brwon fox jmps over the lazzy dog" | aspell -a

This command will read the input from the echo command and check the spelling of each word in the input. Any misspelled words will be displayed as they are encountered, along with possible corrections.

Here is an example of the output:

$ echo "The qick brwon fox jmps over the lazzy dog" | aspell -a

@(#) International Ispell Version 3.1.20 (but really Aspell 0.60.8)
*
& qick 44 4: quick, wick, kick, quack, Dick, Mick, Nick, Rick, dick, hick, lick, mick, nick, pick, rick, sick, tick, QC, Jock, cock, jock, kicky, quirk, Jack, Keck, Kirk, jack, KC, kc, quicker, quickie, quirky, icky, ck, kike, kicks, Gk, cg, kicker, Crick, click, crick, quick's, kick's
& brwon 29 9: Brown, brown, Bryon, brewing, Browne, Breton, Brno, Byron, baron, boron, brawn, Bruno, Barron, Brain, brain, bruin, Briton, baryon, Bran, bran, Bowen, Brian, Bryan, barony, brawny, Brownie, browner, brownie, rowan
*
& jmps 100 19: jumps, jump's, Japs, amps, imps, umps, Kemp's, Kempis, camps, comps, gimps, humps, jumpers, MIPS, MP's, jams, jump, maps, mops, James, Jap's, Jim's, jam's, japes, jeeps, jumpy, kips, Campos, amp's, camp's, campus, comp's, compos, gimp's, imp's, jambs, ump's, GPS, cps, bumps, damps, dumps, hemp's, hump's, lamps, limps, lumps, mumps, pimps, pumps, ramps, romps, rumps, sumps, tamps, temps, vamps, wimps, Cm's, GM's, caps, cops, cups, gaps, gyps, map's, mop's, jumper's, Jame's, Jami's, Jeep's, Kip's, jeep's, kip's, jamb's, GP's, jape's, bump's, damp's, dump's, lamp's, limp's, lump's, pimp's, pomp's, pump's, ramp's, romp's, rump's, sump's, temp's, vamp's, wimp's, GOP's, Gap's, cap's, cop's, cup's, gap's, gyp's
*
*
& lazzy 37 33: lazy, Lizzy, jazzy, Lacy, lacy, laze, Lacey, lays, lay, lazily, Las, Liz, Luz, Lizzie, lazier, Lady, hazy, jazz, lady, razz, Liza, La's, Laos, Lars, Lucy, la's, lace, lase, lass, laws, lazed, lazes, Lao's, law's, lay's, Lizzy's, laze's
*

Create a Custom Dictionary From a File

To create a new dictionary file "custom.dict" from the "words.txt" file, you would use the following command:

aspell create master custom.dict < words.txt

This command will create a new dictionary file "custom.dict" from the words in the "words.txt" file. The dictionary file can then be used for spell-checking with the -d flag.

The "custom.dict" file created with the aspell create command will contain a list of words, one per line, that will be used as the custom dictionary for spell-checking.

For example, if the "words.txt" file contains the following words:

quick
brown
fox
jumps
lazy
dog

Then the "custom.dict" file will contain these words in the same order, one per line:

quick
brown
fox
jumps
lazy
dog

The custom dictionary file can be used with the -d flag to specify the dictionary to use for spell-checking.

This allows you to create a custom dictionary that includes words that may not be in the default dictionary, or to exclude words that are in the default dictionary but that you do not want to consider as correct spellings. You can edit the "custom.dict" file directly to add or remove words as needed.

Set and Use Custom Dictionary From Standard Input

To set the dictionary to use for spell-checking to "custom.dict" and check the spelling of the input from standard input, you would use the following command:

echo "The qick brwon fox jmps over the lazzy dog" | aspell -d custom.dict -a

This command will set the dictionary to use for spell-checking to "custom.dict" and then read the input from the echo command and check the spelling of each word in the input. Any misspelled words will be displayed as they are encountered, along with possible corrections.