Open System Services Programmer's Guide

1. The following information can be derived about the acos() function:
• Specified in the ISO/ANSI C standard.
• Can be called from Guardian and OSS modules.
• Can be called from Guardian and OSS processes.
• When called from a Guardian module, it causes an exception on arithmetic overflow;
when called from an OSS module, it does not.
2. The following information can be derived about the edlseek() function:
• Is an extension specified by HP.
• Can be called only from Guardian modules.
• Can be called from Guardian and OSS processes.
• Requires Guardian parameters.
• Operates only on Guardian objects.
• Because it is specified by HP, it requires the _TANDEM_SOURCE feature test macro.
3. The following information can be derived about the edpwent() function:
• Specified in the X/OPEN specification.
• Can be called only from OSS modules.
• Can be called only from OSS processes.
• Requires the the _XOPEN_SOURCE_EXTENDED or _TANDEM_SOURCE feature test macro.
4. The following information can be derived about the free() function:
• Specified in the ISO/ANSI C standard.
• Can be called from Guardian and OSS modules.
• Can be called from Guardian and OSS processes.
• If the CHECK pragma is specified, the function performs identical parameter validation
in both Guardian and OSS modules. If the NOCHECK pragma is specified, the function
does not perform extra parameter validation in Guardian and OSS modules.
5. The following information can be derived about the rename() function:
• Specified in the ISO/ANSI C standard.
• Can be called from Guardian and OSS modules.
• Can be called from Guardian and OSS processes.
• When called from a Guardian module, it requires Guardian parameters; when called
from an OSS module, it requires OSS parameters.
• Guardian function operates only on Guardian objects; OSS function operates on OSS
objects and limited Guardian objects.
6. The following information can be derived about the signal() function:
• Specified in the ISO/ANSI C standard.
• Can be called only from a Guardian module in a Guardian process or from an OSS
module in an OSS process. The module and process environments must be the same. The
function’s behavior is different in each environment.
• Guardian function operates only on Guardian objects; OSS function operates only on
OSS objects.
Using the API Interoperability Table 481