LOCK (access): Difference between revisions
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(Created page with "The LOCK statement restricts access to parts of a file by other programs or processes. {{PageSyntax}} :LOCK [#]{{Parameter|fileNumber%}} :LOCK [#]{{Parameter|fileNumber%}}, {{Parameter|record&}} :LOCK [#]{{Parameter|fileNumber%}}, [{{Parameter|firstRecord&}}] TO {{Parameter|lastRecord&}} {{PageDescription}} * {{Parameter|fileNumber%}} is the file number of the file to lock. * In the first syntax, the entire file is locked. * In the second syntax, {{Pa...") |
TheSnowDog (talk | contribs) m (QuickBASIC capitialisation) |
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==QBasic/ | ==QBasic/QuickBASIC== | ||
* Required DOS '''SHARED.EXE''' to be run for QBasic to use networking access modes. No longer required. | * Required DOS '''SHARED.EXE''' to be run for QBasic to use networking access modes. No longer required. | ||
Revision as of 09:38, 29 April 2022
The LOCK statement restricts access to parts of a file by other programs or processes.
Syntax
Description
- fileNumber% is the file number of the file to lock.
- In the first syntax, the entire file is locked.
- In the second syntax, record& is the record number of the file to lock.
- In the third syntax, the records or bytes in the range [firstRecord&,lastRecord&] are locked. If firstRecord& is omitted, it is assumed to be one (the first record or byte).
- For files opened in BINARY mode, each record corresponds to a single byte.
- LOCK and UNLOCK statements are always used in pairs and each statement must match the other one.
- Files must be unlocked using UNLOCK before other programs can access them, and before the file is closed.
- Keyword not supported in Linux or macOS versions
QBasic/QuickBASIC
- Required DOS SHARED.EXE to be run for QBasic to use networking access modes. No longer required.
See also