Busy box Read file line by line

Question

There is no read applet comming with busy box.

Is there any way to read a txt file line by line using busybox?

What I have now is

while read line
do
     echo $line
done < "$InputFile"

Answer 1

read is a shell builtin (it couldn't set a shell variable if it were not).

So, if your busybox sh is based on ash, it's:

while IFS= read -r line <&3; do
  printf '%s\n' "$line"
done 3< "$InputFile"

Like in any POSIX shell. But like with any shell, using while read loops to process text is generally bad shell scripting practice.

Above, you need:

• IFS= otherwise leading and trailing unescaped spaces and tabs are stripped from the lines
• -r, otherwise backslashes are treated as an escape character and removed (unless escaped)
• printf, not echo which wouldn't work for lines that are for instance -nene
• "$line" quoted (not $line) otherwise the content of the line is split on spaces and tabs, and globbing patterns expanded.
• <&3 and 3< ..., if you need access to the original stdin within the loop.

If the file contains characters after the last line and you want to display them, you can add after the loop:

[ -z "$line" ] || printf %s "$line"

Note that that loop cannot handle binary data (the NUL character).

Answer 2

I managed to solve my requirement by using

head testInputs/test1 -n $getLineNum | tail -n 1

getLineNum increments on each while loop.

but it is not the exact answer for my question.

Also you need to add some thing like #EOF at the last line and search for it to break the loop.