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4.2.4 Extracting Words

The final task in this section extends the word count program to print each word in the input stream of characters.

Task

WDS: Read characters until end of file and keep a count of characters, lines, and words. Also, print each word in the input on a separate line.

The logic is very similar to that of the previous program, except that a character is printed if it is in a word, i.e. if inword is True. We will decide whether to print a character only after a possible state change of inword has taken place. That way when inword changes from False to True (the first character of a word has been found) the character is printed. When inword changes from from True to False (a delimiter has been found ending the word) it is not printed, instead we print a newline because each word is to be printed on a new line. So our algorithm is:

initialize counts to zero, set inword to False
     while the character read, ch, is not EOF
          increment character count, chrs
          if ch is a newline
               increment line count, lns
          if NOT inword AND ch is NOT delimiter
               increment word count, wds
               set inword to True
          else if inword and ch is delimiter
               set inword to False
               print a newline
          if inword
               print ch
     print results

The program file is compiled and linked with chrutil.c. and the following sample session is produced.

Sample Session:

• ***Word Program***
• Type characters, EOF to quit
• Now is the time for all good men
• Now
• is
• the
• time
• for
• all
• good
• men
• '136D
• Lines = 1, Words = 8, Characters = 33