If line ( and I mean line, not line [ 0 ] ) hasn't been initialised then dereferencing it ( which is what line [ 0 ] does ) will mean examining some unknown ( and very often illegal ) chunk of memory.
22.
Note also that there are occasions when dereferencing the NULL " is " intentional and well defined; for example BIOS code written in C for 16-bit real-mode x86 devices may write the IDT at physical address 0 of the machine by dereferencing a NULL pointer for writing.
23.
Note also that there are occasions when dereferencing the NULL " is " intentional and well defined; for example BIOS code written in C for 16-bit real-mode x86 devices may write the IDT at physical address 0 of the machine by dereferencing a NULL pointer for writing.
24.
The second graph shows the previous example, but now enriched with a few of the triples from the documents that result from dereferencing http : / / schema . org / Person ( green edge ) and http : / / www . wikidata . org / entity / Q1731 ( blue edges ).
25.
A pattern P'is said to be more specific than a pattern P if and only if P'can be obtained from P by a ) dereferencing a wild card or b ) instantiating a bracketed literal to a literal, or c ) by appending a string of literals, bracketed literals or / and wild cards to the right of P, or d ) by prepending a string of literals, bracketed literals or / and wild cards to the left of P.
