standard linux C base in DOS?

[Arkhan]

I have a program done in Linux that uses strndup and some other things....

when it is compiled on a DOS computer w/ gcc, it complains like this:

symtab.c:58: warning: incompatible implicit declaration of built-in function 'st
rndup'
symtab.c:58: warning: incompatible implicit declaration of built-in function 'st
rlen'
symtab.c: In function 'symEqual':
symtab.c:102: warning: incompatible implicit declaration of built-in function 's
trlen'
gcc -c terminals.c -o terminals.o
terminals.c: In function 'markTerminals':
terminals.c:72: warning: incompatible implicit declaration of built-in function
'malloc'
terminals.c: In function 'freeNonTerminals':
terminals.c:153: warning: incompatible implicit declaration of built-in function
 'free'
gcc -c firsts.c -o firsts.o
firsts.c: In function 'findFirsts':
firsts.c:69: warning: incompatible implicit declaration of built-in function 'ma
lloc'
firsts.c: In function 'addToFirst':
firsts.c:295: warning: incompatible implicit declaration of built-in function 'm
alloc'
firsts.c:310: warning: incompatible implicit declaration of built-in function 'm
alloc'
firsts.c:332: warning: incompatible implicit declaration of built-in function 'f
ree'
firsts.c: In function 'freeFirsts':
firsts.c:477: warning: incompatible implicit declaration of built-in function 'f
ree'
firsts.c:484: warning: incompatible implicit declaration of built-in function 'f
ree'

is there some sort of include for DOS that lets the Linux standard stuff work properly?

I have tried to snag the relevant functions and stick them in a header file but it doesnt seem to be working.. i might have just done that wrong...