Text-search command reference

Course resources · class 2 exercise · class 3 exercise

Use these commands with story.txt, the course copy of 「蜘蛛の糸」. Open a terminal.

Folders and input

Command	Meaning
`pwd`	Show the current folder’s path
`ls`	List its contents
`mkdir -p dh-b-2026`	Create a working folder if needed
`cd dh-b-2026`	Move into that folder from its parent; run once

The download overwrites any existing story.txt in the current folder. Keep annotations in a separate file.

curl -fL -o story.txt https://soranoha.org/works/000092_000879/plaintext

-f fails on HTTP errors; -L follows redirects; -o sets the output file path.

Search and counting units

Command	Output
`grep --color=auto -nF 'のぼ' story.txt`	Matching lines with line numbers
`grep -cF 'のぼ' story.txt`	Number of matching lines
`grep -oF 'のぼ' story.txt`	Each occurrence on a separate line

--color=auto highlights matches in a terminal on macOS and Linux without altering matches or counts.

To count occurrences, pipe the output:

grep -oF 'のぼ' story.txt | wc -l

-F matches exact strings. A pipe (|) sends output into the next command; wc -l prints the incoming line count. Use straight quotes ('), not curved quotes (‘ ’). Output after each stage, illustrated.

The bundled text has 5 matching lines and 12 occurrences, including あのぼんやり. Counting units illustrated.

How can I save search output to a file?

Paste the command and output into your notes, or use > to save the output:

grep -nF '落ち' story.txt > down.txt

> writes the output to down.txt, replacing a file of the same name. Keep the command in your notes as well.

Search with a pattern

With -E, grep reads its argument as a regular expression. It cannot be combined with -F.

Command	Output
`grep -onE 'のぼ.' story.txt`	`のぼ` and the next character, one per line with line numbers
`grep -oE 'のぼ.' story.txt \| sort \| uniq -c`	A count for each following character
`grep -oE 'のぼ[っりるれ]' story.txt \| wc -l`	Occurrences followed by one of the bracketed characters

Symbol	Meaning
`.`	Any one character
`[っりるれ]`	One character from inside the brackets

The bundled text has 12 matches for のぼ. (including one のぼん) and 11 for のぼ[っりるれ].

Recover from a problem

Problem	Action
Download fails	Save the local text copy as `story.txt` in the working folder
`No such file`	Check the current folder and filename with `pwd` and `ls`
Terminal waits for more input	Press Ctrl+C; check that both quotes are present
No matches	Check the spelling in the source
`.` does not match one character and the output is garbled	Check that `locale` shows `UTF-8`, and set the terminal’s character encoding to UTF-8
`grep` is not recognized on Windows	Close Command Prompt or PowerShell; open Ubuntu on WSL
A command is unavailable	Follow Set up `ling`; for the class 2 homework, browser search also works