# Cheatsheet & Examples: sort

The `sort` command is used to sort lines of text files in alphabetical, numerical, or other specified orders. It can also handle unique entries, reverse sorting, and field-based sorting.

## Sorting a file alphabetically  
Example Usage:  
`sort filename.txt`  

What it does:  
Sorts the contents of the file in ascending alphabetical order.  

Command-line Arguments Explained:  
- `filename.txt`: The text file to be sorted.  

## Sorting numerically  
Example Usage:  
`sort -n filename.txt`  

What it does:  
Sorts the file based on numeric values rather than lexicographical order.  

Command-line Arguments Explained:  
- `-n`: Enables numeric sorting.  

## Sorting in reverse order  
Example Usage:  
`sort -r filename.txt`  

What it does:  
Sorts the file in descending order (reverse of default behavior).  

Command-line Arguments Explained:  
- `-r`: Reverses the sort order.  

## Removing duplicate lines  
Example Usage:  
`sort -u filename.txt`  

What it does:  
Sorts the file and removes duplicate lines, keeping only unique entries.  

Command-line Arguments Explained:  
- `-u`: Removes duplicate lines after sorting.  

## Sorting by specific fields  
Example Usage:  
`sort -k 2,2 filename.txt`  

What it does:  
Sorts the file based on the second field (column), using whitespace as the default delimiter.  

Command-line Arguments Explained:  
- `-k 2,2`: Specifies the sort key starting and ending at the second field.  

## Specifying a custom delimiter  
Example Usage:  
`sort -t ',' -k 2,2 filename.csv`  

What it does:  
Sorts a CSV file by the second field, using a comma as the delimiter.  

Command-line Arguments Explained:  
- `-t ','`: Sets the delimiter to a comma.  
- `-k 2,2`: Sorts by the second field.  

## Merging multiple sorted files  
Example Usage:  
`sort -m file1.txt file2.txt`  

What it does:  
Merges multiple already-sorted files into a single sorted output.  

Command-line Arguments Explained:  
- `-m`: Merges sorted input files without re-sorting.  

## Checking if a file is already sorted  
Example Usage:  
`sort -c filename.txt`  

What it does:  
Verifies if the file is already sorted; if not, it reports an error.  

Command-line Arguments Explained:  
- `-c`: Checks the input for sorted order.  

## Performing a stable sort  
Example Usage:  
`sort -s filename.txt`  

What it does:  
Sorts the file without changing the order of equal lines.  

Command-line Arguments Explained:  
- `-s`: Ensures a stable sort (maintains original order for equal elements).  

## Ignoring case during sorting  
Example Usage:  
`sort -f filename.txt`  

What it does:  
Sorts lines case-insensitively (e.g., treating "Apple" and "apple" as equal).  

Command-line Arguments Explained:  
- `-f`: Ignores case distinctions during sorting.  

## Skipping leading whitespace or characters  
Example Usage:  
`sort -b filename.txt`  

What it does:  
Ignores leading whitespace or characters before sorting.  

Command-line Arguments Explained:  
- `-b`: Skips leading whitespace or characters in each line.  

## Redirecting output to a file  
Example Usage:  
`sort input.txt > output.txt`  

What it does:  
Sorts the input file and writes the sorted output to a specified file.  

Command-line Arguments Explained:  
- `input.txt`: The file to sort.  
- `> output.txt`: Redirects the output to `output.txt` instead of the terminal.