Introduction grep End of Line
grep is an essential command for text searching, but many beginners are unsure how to search based on a condition at the end of a line.
Once you understand how to specify the end of a line, you can efficiently extract things like specific file extensions or patterns at the end of log entries.
This article explains everything in detail, from the basics to more advanced usage
Reference: GNU grep
Basic grep Syntax for End of Line
Create the file
cat << 'EOF' > input.txt
apple
banana
orange
grape
melon
apple pie
green apple
banana
orange juice
pineapple
EOFCommand to run
grep 'apple$' input.txtResult
apple
green apple
pineappleCommand to run
grep 'juice$' input.txtResult
orange juiceCommand to run
grep 'banana$' input.txtResult
banana
bananaHow it works
| Item | Description |
|---|---|
| $ | Anchor (metacharacter) representing the end of a line |
| grep ' |
Searches only for lines that end with the specified string |
| Difference from partial match | Matches only when the end of the line matches, not the middle |
| Example use case | Used for searching file extensions or extracting lines with a specific suffix |
Explanation
In grep, using $ lets you specify the end of a line.
This is useful when you only want to extract data that ends with the specified string.
grep End of Line Search for a Specific String
Create the file
cat << 'EOF' > input.txt
apple
banana
grape
orange
pineapple
green apple
red apple
EOFCommand to run
grep 'apple$' input.txtResult
apple
pineapple
green apple
red appleHow it works
| Item | Description |
|---|---|
| Command | grep 'apple$' input.txt |
| apple | The string you want to search for. |
| $ | In regular expressions, this represents the "end of line" and searches only for lines ending in apple. |
| input.txt | The file to search. |
Explanation
grep supports regular expressions, and by adding $ you can search only for strings that match the end of a line.
Using an end-of-line match lets you efficiently extract only lines with a specific suffix.
Combining grep End of Line and Start of Line for an Exact Match
Create the file
cat << 'EOF' > input.txt
apple
Apple
apple pie
pineapple
apple
EOFCommand to run
grep '^apple$' input.txtResult
apple
appleHow it works
| Pattern | Meaning |
|---|---|
| ^ | Represents the start of a line |
| apple | The string you want to search for |
| $ | Represents the end of a line |
| ^apple$ | Searches only for lines where the entire content, from start to end, is exactly apple |
Explanation
By combining start of line (^) and end of line ($) as in grep '^apple$', you can search only for lines whose entire content matches the string exactly.
Lines like apple pie or pineapple, which merely contain the string, will not match.
How to Search Multiple grep End of Line Patterns
Create the file
cat << 'EOF' > input.txt
error
warning
info
error.log
warning.log
info.log
server-error
server-warning
server-info
backup-error
backup-warning
backup-info
EOFCommand to run
grep -E '(error|warning)$' input.txtResult
error
warning
server-error
server-warning
backup-error
backup-warningHow it works
| Item | Description |
|---|---|
| grep | Command that searches text for lines matching a condition |
| -E | Enables extended regular expressions, allowing you to use | |
| (error|warning) | Matches either error or warning |
| $ | Represents the end of a line, matching only lines that end with the specified string |
Explanation
Multiple end-of-line patterns can be searched in a single grep call by combining extended regular expressions with the OR operator (|).
Adding $ ensures a match only occurs when the specified string is at the end of the line.
Using grep to Find Lines Ending in Digits, Letters, or Symbols
Create the file
cat << 'EOF' > input.txt
apple
banana123
orange!
grape?
melon.
peach-
kiwi_
lemon9
cat@
dog#
bird$
fish%
EOFCommand to run
grep '[0-9]$' input.txtResult
banana123
lemon9Command to run
grep '[[:alpha:]]$' input.txtResult
appleCommand to run
grep '[[:punct:]]$' input.txtResult
orange!
grape?
melon.
peach-
kiwi_
cat@
dog#
bird$
fish%How it works
| Item | Description |
|---|---|
| $ | Anchor representing the end of a line |
| [0-9] | Matches a single digit from 0-9 |
| [[:alpha:]] | Matches a single letter (A-Z, a-z) |
| [[:punct:]] | Matches a single symbol character (! @ # $ % . ? - etc.) |
| grep '[pattern]$' | Searches only for lines whose end matches the specified character class |
Explanation
$ is the regular expression anchor representing the end of a line.
By combining it with character classes, you can easily extract lines that end in digits, letters, or symbols.
How to Use grep to Find Trailing Whitespace at the End of a Line
Create the file
cat << 'EOF' > input.txt
normal line
space at end
tab at end
multiple spaces at end
no trailing whitespace
EOFCommand to run
grep -nE '[[:blank:]]+$' input.txtResult
2:space at end
3:tab at end
4:multiple spaces at end How it works
| Pattern | Meaning |
|---|---|
| grep | Command that searches text |
| -n | Displays the line number of the match |
| -E | Uses extended regular expressions |
| [[:blank:]] | Matches a half-width space or a tab |
| + | Indicates the preceding character repeats one or more times |
| $ | Represents the end of a line, so only trailing whitespace is matched |
Explanation
Using [[:blank:]]+$ lets you detect only the spaces or tabs at the end of a line.
This regular expression is often used to check for unwanted trailing whitespace.
How to Use grep to Find Blank Lines
Create the file
cat << 'EOF' > input.txt
apple
banana
grape
orange
melon
EOFCommand to run
grep '$' input.txtResult
apple
banana
grape
orange
melon
Command to run
grep -n '^$' input.txtResult
2:
5:
8:How it works
| Pattern | Meaning | Use |
|---|---|---|
| $ | Matches the end of a line | Matches every line (including blank lines) |
| ^ | Matches the start of a line | Represents the beginning of a line |
| ^$ | End of line immediately after start of line | Matches only blank lines with no characters at all |
| -n | Displays line numbers | Lets you check which line numbers are blank |
Explanation
To search for blank lines with grep, use ^$, which combines the start of line (^) and end of line ($) with nothing in between.
Adding the -n option lets you confirm not just the blank lines themselves, but also the line numbers where they occur.
Using the grep -E Option for End of Line Search
Create the file
cat << 'EOF' > input.txt
apple
banana
orange
grape
apple.txt
banana.txt
orange.log
grape.csv
README
EOFCommand to run
grep -E '.txt$' input.txtResult
apple.txt
banana.txtCommand to run
grep -E 'e$' input.txtResult
apple
orange
grapeHow it works
| Item | Description |
|---|---|
| grep | Command that searches for lines matching a condition |
| -E | Option that enables extended regular expressions |
| $ | Metacharacter representing the end of a line |
| \.txt$ | Searches for lines ending in .txt (the . is escaped as \.) |
| e$ | Searches for lines that end with the letter e |
Explanation
grep -E lets you use extended regular expressions, and $ lets you search only for strings that match the end of a line.
This is commonly used to extract file extensions or lines with a particular ending.
How to Search grep End of Line Across Multiple Files
Create the file
cat << 'EOF' > file1.txt
apple
banana
orange
grape
EOFCreate the file
cat << 'EOF' > file2.txt
melon
banana
pineapple
orange
EOFCreate the file
cat << 'EOF' > file3.txt
strawberry
apple
kiwi
banana
EOFCommand to run
grep 'banana$' file1.txt file2.txt file3.txtResult
file1.txt:banana
file2.txt:banana
file3.txt:bananaCommand to run
grep 'orange$' file1.txt file2.txt file3.txtResult
file1.txt:orange
file2.txt:orangeCommand to run
grep -H 'apple$' file1.txt file2.txt file3.txtResult
file1.txt:apple
file2.txt:pineapple
file3.txt:appleHow it works
| Item | Description |
|---|---|
| grep | Command that searches for a specified pattern |
| banana$ | $ represents the end of a line, so only lines ending in banana match |
| file1.txt file2.txt file3.txt | Searches multiple files at once |
| -H | Always shows the filename before a matched line |
Explanation
By adding $ to the end of the search string, grep matches only strings found at the end of a line.
When you specify multiple files, you can search all of them for matching lines in a single execution.
How to Specify an End of Line Condition in a Recursive grep Search
Create the file
mkdir -p sample/{dir1,dir2}Create the file
cat << 'EOF' > sample/dir1/file1.txt
error
error log
warning
EOFCreate the file
cat << 'EOF' > sample/dir2/file2.txt
error
fatal error
error.log
EOFCommand to run
grep -r 'error$' sampleResult
sample/dir2/file2.txt:error
sample/dir2/file2.txt:fatal error
sample/dir1/file1.txt:errorHow it works
| Item | Description |
|---|---|
| grep | Command that searches text |
| -r | Searches a directory recursively |
| error$ | $ represents the end-of-line anchor, matching only lines that end with "error" |
| Non-matching examples | error log and error.log do not match because the line does not end in error |
Explanation
Using the regular expression $ in grep lets you search based on the end of a line.
Combined with -r, you can efficiently search every file in a directory tree for lines matching your end-of-line condition.
A Practical Example of grep End of Line Search in a Log File
Create the file
cat << 'EOF' > input.txt
2025-01-10 10:00:01 INFO Application started
2025-01-10 10:01:15 ERROR Database connection failed
2025-01-10 10:02:30 INFO User login success
2025-01-10 10:03:45 ERROR Disk full
2025-01-10 10:04:50 INFO Backup completed
EOFCommand to run
grep 'failed$' input.txtResult
2025-01-10 10:01:15 ERROR Database connection failedCommand to run
grep 'full$' input.txtResult
2025-01-10 10:03:45 ERROR Disk fullCommand to run
grep 'success$' input.txtResult
2025-01-10 10:02:30 INFO User login successHow it works
| Item | Description |
|---|---|
| grep | Command that searches for lines matching the specified pattern |
| $ | Regular expression metacharacter representing "end of line" |
| failed$ | Searches only for lines ending in failed |
| full$ | Searches only for lines ending in full |
| success$ | Searches only for lines ending in success |
Explanation
Using the regular expression $ in grep matches a string only when it occurs at the end of a line.
This is convenient when you want to extract status messages or error messages found at the end of a log file.
Causes and Solutions When grep End of Line Search Does Not Work
Create the file
cat << 'EOF' > input.txt
apple
apple
banana
orange
apple$
EOFCommand to run
grep "apple$" input.txtResult
appleCommand to run
grep -E "apple$" input.txtResult
appleCommand to run
grep '$$' input.txtResult
apple$Command to run
grep -n "apple " input.txtResult
2:apple How it works
| Description | Command | Behavior |
|---|---|---|
| End of line specifier | $ | Matches only when the pattern is found at the very end of the line |
| $ as a literal character | \$$ | Escapes $ so it is searched for as a literal character |
| Basic regular expressions | grep | Interprets regex symbols such as $ |
| Extended regular expressions | grep -E | Allows access to more regex features |
| Trailing whitespace | grep "apple " | Invisible whitespace characters also count as part of the match condition |
Explanation
When a grep end-of-line search doesn't behave as expected, the main cause is usually that $ is being interpreted as the regular-expression symbol for "end of line."
Also, if there is trailing whitespace or a special character at the end of a line, what you see and what is actually in the string can differ, causing the search results to be off.
Commonly Used grep Options for End of Line Searches
Create the file
cat << 'EOF' > input.txt
error
error
error.log
test error
EOFCommand to run
grep 'error$' input.txtResult
error
test errorCommand to run
grep -n 'error$' input.txtResult
1:error
4:test errorCommand to run
grep -E 'error$' input.txtResult
error
test errorCommand to run
grep -i 'ERROR$' input.txtResult
error
test errorCommand to run
grep -v 'error$' input.txtResult
error
error.logHow it works
| Command / Option | Role | How it works for end-of-line search |
|---|---|---|
| grep ' |
End-of-line match search | $ specifies the terminating position of the string |
| -n | Show line numbers | Lets you confirm the position of each match |
| -E | Extended regular expressions | Easier to combine with more complex regular expressions |
| -i | Ignore case | Treats ERROR$ and error$ as the same |
| -v | Inverted match | Retrieves lines that do NOT match the end-of-line condition |
Explanation
An end-of-line search in grep uses the regular expression $.
Since $ means "the end of the line," it is often used in log analysis and configuration-file searches to extract lines ending in a specific character or string.
Summary of grep End of Line Points
Once you grasp the basics of regular expressions, grep end-of-line searches can be applied to a wide range of situations.
After understanding the basic syntax, using exact matches, multiple conditions, the -E option, and multi-file searches as needed can greatly improve your efficiency.
Once you have mastered what's covered here, you'll be able to confidently apply it to a variety of text and log analysis tasks.
