How it works...

In grep, ^ is the word-start marker character and the $ character is the word-end marker. The -q option suppresses any output, making the grep command quiet.

Alternatively, we can use the spell–check, aspell, to check whether a word is in a dictionary or not:

#!/bin/bash  
#Filename: aspellcheck.sh 
word=$1  

output=`echo \"$word\" | aspell list`  

if [ -z $output ]; then  
        echo $word is a dictionary word;  
else  
        echo $word is not a dictionary word;  
fi  

The aspell list command returns output text when the given input is not a dictionary word, and does not output anything when the input is a dictionary word. A -z command checks whether $output is an empty string or not.

The look command will display lines that begin with a given string. You might use it to find the lines in a log file that start with a given date, or to find words in the dictionary that start with a given string. By default, look searches /usr/share/dict/words, or you can provide a file to search.

$ look word

Alternatively, this can be used:

$ grep "^word" filepath

Consider this example:

$ look android
android
android's
androids

Use this to find lines with a given date in /var/log/syslog:

$look 'Aug 30' /var/log/syslog