grep.c should #include <strings.h> because it uses strcasecmp, and POSIX says it is declared in <strings.h> 

Not doing so results in a warning about an undeclared function on some systems (including Kalray k1c), thus possibly in incorrect code being generated. 


Directeur de recherche au CNRS, laboratoire VERIMAG, équipe PACSS 
http://www-verimag.imag.fr/~monniaux/