Null-terminated string: Difference between revisions

Revision as of 01:19, 3 January 2007

Revision as of 01:07, 7 March 2007

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{{dablink|This article is on strings in computer programming. A number of [[stringed instrument]]s, including the [[viola]] and [[cello]], have a string that, when played open, produces the [[note|note C]]. This is usually referred to as the '''C string'''.}}

In computing, '''C strings''' are [[character string|character sequence]]s stored as one-dimensional [[character (computing)|character]] [[array]]s and terminated with a [[null character]] ('\0', orcalled ASCIINUL 0in ASCII). The name refers to the ubiquitous [[C (programming language)|C programming language]] using this [[string (computer science)#Representations|string representation]], and is used elsewhere to distinguish this often-used representation from others.

The null-termination characteristic has historically created [[computer insecurity|security problems]] related to the length of the string. If the null character is not added to the end of the string for some reason, any following non-related memory area is also processed as a part of the character sequence. This can lead to program crashes or leakage of program internal information to attackers or non-understanding users. This problem can (and should) be prevented by appropriate error checking.