debugging - Segmentation fault strcmp in c -

i'm trying run program in c takes in text file , string user , searches file string. keeps getting segmentation fault , gdb pointing me towards function not sure problem is. pretty sure has strcmp call not sure. issue appreciated.

int intable( const char *s ) {     int i;      for( i=0; i<numlines; ++i )     {         if( strcmp( st[i], s ) == 0 )                 return 1;     }      return 0; } 

you should check use strcmp(), api is:

int strcmp(const char *str1, const char *str2) 

you must:

1) validate st[i], first argument pointer.

2) make sure st[i] & s has null terminator '\0'`.

3) check st[i] & s pointing allocated place in memory before calling strcmp().