EOF

[abbreviation, `End Of File']

[techspeak] The {out-of-band} value returned by C's sequential character-input functions (and their equivalents in other environments) when end of file has been reached. This value is usually -1 under C libraries postdating V6 Unix, but was originally 0. DOS hackers think EOF is ^Z, and a few Amiga hackers think it's ^.
[Unix] The keyboard character (usually control-D, the ASCII EOT (End Of Transmission) character) that is mapped by the terminal driver into an end-of-file condition.
Used by extension in non-computer contexts when a human is doing something that can be modeled as a sequential read and can't go further. "Yeah, I looked for a list of 360 mnemonics to post as a joke, but I hit EOF pretty fast; all the library had was a {JCL} manual." See also {EOL}.