Thread: #include<math.h>

Hi,

I am working in linux Redhat7.1, P3 system.

Whenever I compile a program which has a math function, I use the command:

cc filename.c -lm

I have to do this inspite of including math.h

The errors that were displayed when I didnot use -lm are as follows:::
***********************************************

bash-2.04$ cc test.c
/tmp/ccUQaDNH.o: In function `main':
/tmp/ccUQaDNH.o(.text+0x1e): undefined reference to `sin'
/tmp/ccUQaDNH.o(.text+0x4a): undefined reference to `sqrt'
collect2: ld returned 1 exit status
bash-2.04$ cc test.c -lm
*---------------------------------------------

What does this -lm signify and why should I give this.

Ashesh

In addition to math.h which other *.h files will need me to add switches like "-lm"

ashesh