# Sort / Compare / Count Read and insert file content ```bash sed -r ``` ## Sort

Command	Description
`sort [file]`	Alphabetical, ascending
`cat [file] \| sort`	Pipe output to `sort`.
`sort -n`	Sort numerically.
`sort -r`	Reverses the result of comparisons, producing a descending order sort.
`sort -k`	Specifies a sort key.
`sort -k2`	Sorts by second column.
`sort -k 2n,2`	Sorts numerically based on the second field, ignoring leading whitespace in that field.
`sort -k 1b`	Sorts by the first word in each line, ignoring case distinctions (`-b`).
`sort -u`	Outputs only the first of an equal run.
`sort -t`	Sets the field delimiter.
`sort -t ',' -k 2`	Sort lines by the second field

Sorts data.csv first by the second field numerically in descending order, then by the first field ignoring case: ```bash sort -k 2n,2r -k 1f data.csv ``` Sorts ps output by CPU% descending, then by PID (process ID): ```bash ps aux | sort -nrk 3,3 -k 8 ``` ## Compare ### Choosing the right command

Command	Description
`diff`	For line-by-line text comparison
`cmp`	For byte-level comparison
`comm`	For comparing sorted lists
`diffstat`	For quick statistics
`meld`	For visual comparison
`md5sum`	For verifying file integrity
`sha256sum`	For verifying file integrity

### Commands

Command	Description
`diff <file1> <file2>`	Compare two files line by line.
`diff -n <file1> <file2>`	Suppresses line numbers.
`diff -i <file1> <file2>`	Ignore case differences in file contents.
`diff -u <file1> <file2>`	Produce a unified format diff, showing several lines of context.
`diff -q <file1> <file2>`	Report only when files differ, without detailing the differences.
`diff -w <file1> <file2>`	Ignore all whitespace changes.
`diff -b <file1> <file2>`	Ignore changes in the amount of whitespace.
`diff --left-column <file1> <file2>`	Show line numbers for differences.
`cmp <file1> <file2>`	Byte-by-byte comparison.
`cmp -l <file1> <file2>`	Show all differences between the files.
`cmp -s <file1> <file2>`	Silent mode, do not write anything, just return an exit status.
`comm <file1> <file2>`	Compare two sorted files line by line.
`comm -1 -2 <file1> <file2>`	Suppress output of specified columns (1 and 2), showing only lines common to both files.
`diff3 <file1> <file2> file3.txt`	Compare three files line by line.
`diff3 -m <file1> <file2> file3.txt`	Show only conflicting changes among the three files.
`sdiff <file1> <file2>`	Side-by-side comparison of files.
`sdiff -i <file1> <file2>`	Ignore case differences in file contents.
`sdiff -s <file1> <file2>`	Suppress lines common to both files.
`diffstat diff_output`	Read a diff output file and display a histogram of insertions, deletions, and modifications per file.
`meld file1 file2`	Graphical tool to compare and merge files interactively.
`md5sum file`	Calculate MD5 checksum.
`sha256sum file`	Calculate SHA-256 checksum.

## Count

Command	Description
`wc [file]`	Count lines, words, and bytes.
`wc -l [file]`	Count lines.
`wc -w [file]`	Count words.
`wc -c [file]`	Count bytes.
`wc -m [file]`	Count characters.
`awk 'END {print NR}' [file]`	Count lines. `NR` represents the total number of records processed.
`awk '{count++} END {print count}' [file]`	Count lines.
`awk '/error/ {count++} END {print count}' [file]`	Count lines containing "error".
`sed '/^$/d' filename \| wc -l`	Counts non-empty lines.
`sed 's/[^a-zA-Z0-9 ]//g' filename \| wc -w`	Counts alphanumeric words
`sed -n '$=' [file]`	Count lines. `$=` command prints the total number of lines.
`grep pattern [file] \| wc -l`	Alternate way to count lines
`grep -c "[pattern]" [file]`	Lines with pattern match.
`grep -c "[pattern]" <file1> <file2>`	Miltiple files
`grep -o "[pattern]" [file] \| wc -l`	Count pattern matches, including multiple occurrences per line. `-o` outputs each match on a new line.
`grep -r -c "[pattern]" /directory`	Recursive counts lines with pattern match.
`find . -type f \| wc -l`	Count files in a directory and its subdirectories

Recursive by file extension: ```bash grep --include=\*. -ro "[pattern]" | wc -l ``` Recursive counts lines with pattern match: ```bash find / -type f -exec grep -o "[pattern]" {} + | wc -l ``` Uses `awk` to globally substitute (thus count) occurrences of the pattern in each line and sums them up: ```bash awk '{count += gsub(/[pattern]/, "[pattern]")} END {print count}' [file] ``` Count the total number of lines across all files in a directory and its subdirectories: ```bash find . -type f -exec wc -l {} + | awk '{total += $1} END {print total}' ``` --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://www.shellspells.net/linux/file-ops/sort-compare-count.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.