wc

wc produces word, line and byte counts

wc, or “word count,” prints a count of newlines, words, and bytes for each input file.

Options
-c, –bytes print the byte counts.
-m, –chars print the character counts.
-l, –lines print the newline counts.
–files0-from=F read input from the files specified by NUL-terminated names in file F; If F is “-” then read names from standard input.
-L, –max-line-length print the length of the longest line.
-w, –words print the word counts.
–help display a help message, and exit.
–version output version information, and exit.

 

wc myfile.txt

Displays information about the file myfile.txt. Output will resemble the following:

5 13 57 myfile.txt

Where 5 is the number of lines, 13 is the number of words, and 57 is the number of characters.

ls -1 | wc -l

This command returns the number of objects in the current directory It uses the ls command to produce a single-column (-1) listing of the directory contents, which outputs one line per object; this output is piped to wc, which counts the lines (-l), and returns that number.