Reading input files by line using read command in shell scripting skips last line

Question

I usually use the read command to read an input file to the shell script line by line. An example code such as the one below yields a wrong result if a new line isn\'t inser

Answer 1

Use while loop like this:

while IFS= read -r line || [ -n "$line" ]; do
  echo "$line"
done 

Or using grep with while loop:

while IFS= read -r line; do
  echo "$line"
done < <(grep "" file)

Using grep . instead of grep "" will skip the empty lines.

Note:

1. Using IFS= keeps any line indentation intact.

2. You should almost always use the -r option with read.

3. Don't read lines with for

4. File without a newline at the end isn't a standard unix text file.