Shell Programming and Scripting

Thanks, Chubler. But as I'm still learning about these things, could you explain the last few lines of code to me -- I mean the \c part? Zero is the successful exit status or is it 1, I forget.

the -e option of echo is a bash/ksh thing and enables the interpreation of backslash escapes. \c is used to suppress the CR at the end of a string.

So by echoing the variable with \c we duplicate the contents of the file by showing any value without a CR as it was input. Now, if no line exists without a CR at the end of the file, the variable will be blank and so we echo blank without a CR (i.e. nothing).

read returns 0 if more data is available (ie no EOF is read) and non-zero (typically 1) if and EOF is found.

Instead of echo -e you could use printf which works in other shells too:

Code:

printf "%s" "$variable"

Or if you do not want to preserve the non-linefeed ending of the last line (which is not a proper unix text file format)

Code:

while read variable || [ -n "$variable" ]; do
  echo "$variable"
done