Hi, I got an easy problem for you but really difficult for me 'cause I am pretty new to this field
I got header file <math.h> included in my .c file , then I write the code as below:
k = sqrt\(i\); /* both variables k and i are int */
then I cc temp.c
it says like this
undefined symbol first referenced in file
sqrt temp.o
it really makes me confused, so any one would like to give me a hand?
thanks a lot in avance!
Try:
cc -lm temp.c
The sqrt routine is in the math library. So you need to search the math library to build the executable program.
thanks for your suggestion,and I tried as you told me,but it remained the same error,,,
i386ld fatal: Symbol referencing errors. no output written to a.out
would you offer me more details ,thank you.
### first : the sqrt function requires a "double" parameter , and returns a double .
just like this :
/* ---- snip ---- */
double x = 2.0 ;
double y ;
y = sqrt (x) ;
/* ---- snip ---- */
### second : make sure the math library will be found :
$ find / -name libm.a
(it normally will be found in /lib or /usr/lib )
$ echo $LIBPATH or $LD_LIBRARY_PATH (depending on your o.s.) and
make sure the parent dir that contains libm.a is included in it .
### and finally , compile you program as follows :
$ cc -o yourprog yourprog.c -lm
(put the '-lm' at the end of the line)
good luck , and success !
thank you all.
it works by typing "cc temp.c -lm"
-lm should be added at the end of the line.
and I think the type sqrt(1) returns can be changed into int forcefully, so it isn't the right problem lying there.