This post introduces how to count the number of words in a pdf file using wc command. It works on both Linux (Ubuntu) and Mac OS.
Note: you do not need to install anything, it is built-in on your Ubuntu/Mac OS.
Step 1: open a terminal
Step 2: cd to the directory where your pdf file is located
Step 3: issue the following command
$ ps2ascii example.pdf | wc -w
Step 4: Then you should see the number of words in that example.pdf
P.S. the wc command has several arguments, see below.
wc -l: print the number of lines in a file. wc -w: print the number of words in a file. wc -c: print the number of bytes in a file. wc -m: print the number of characters from a file. wc -L: print only the length of the longest line in a file.