#!/bin/bash# strip-comment.sh: Strips out the comments (/* COMMENT */) in a C program.E_NOARGS=0E_ARGERROR=66E_WRONG_FILE_TYPE=67if [ $# -eq "$E_NOARGS" ]then  echo "Usage: `basename $0` C-program-file" >&2 # Error message to stderr.  exit $E_ARGERRORfi  # Test for correct file type.type=`file $1 | awk '{ print $2, $3, $4, $5 }'`# "file $1" echoes file type . . .# Then awk removes the first field, the filename . . .# Then the result is fed into the variable "type."correct_type="ASCII C program text"if [ "$type" != "$correct_type" ]then  echo  echo "This script works on C program files only."  echo  exit $E_WRONG_FILE_TYPEfi  # Rather cryptic sed script:#--------sed '/^\/\*/d/.*\*\//d' $1#--------# Easy to understand if you take several hours to learn sed fundamentals.#  Need to add one more line to the sed script to deal with#+ case where line of code has a comment following it on same line.#  This is left as a non-trivial exercise.#  Also, the above code deletes non-comment lines with a "*/" . . .#+ not a desirable result.exit 0# ----------------------------------------------------------------# Code below this line will not execute because of 'exit 0' above.# Stephane Chazelas suggests the following alternative:usage() {  echo "Usage: `basename $0` C-program-file" >&2  exit 1}WEIRD=`echo -n -e '\377'`   # or WEIRD=$'\377'[[ $# -eq 1 ]] || usagecase `file "$1"` in  *"C program text"*) sed -e "s%/\*%${WEIRD}%g;s%\*/%${WEIRD}%g" "$1" \     | tr '\377\n' '\n\377' \     | sed -ne 'p;n' \     | tr -d '\n' | tr '\377' '\n';;  *) usage;;esac#  This is still fooled by things like:#  printf("/*");#  or#  /*  /* buggy embedded comment */##  To handle all special cases (comments in strings, comments in string#+ where there is a \", \\" ...),#+ the only way is to write a C parser (using lex or yacc perhaps?).exit 0