Hi, all: I have a simple program(see below), it ran without any problem in sun (with sun's compiler). However, when I compiled it in gcc on PC, it crashed at line 13. I tried to use strtok and some other string functions but none of them seems works fine. Does anyone know why? Thanks! Jane Line 1 #include Line 2 #include Line 3 #include Line 4 Line 5 int main() Line 6 { Line 7 Line 8 char *str = "0.12000, 0.0, 0.0"; Line 9 char *ptr; Line 10 float num; Line 11 Line 12 ptr = strchr(str, ','); Line 13 *ptr = '\0'; Line 14 Line 15 num = atof(str); Line 16 Line 17 return 0; Line 18 }