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ELF_AUX_INFO(3) FreeBSD Library Functions Manual ELF_AUX_INFO(3) NAME elf_aux_info - extract data from the elf auxiliary vector of the current process LIBRARY Standard C Library (libc, -lc) SYNOPSIS #include <sys/auxv.h> int elf_aux_info(int aux, void *buf, int buflen); DESCRIPTION The elf_aux_info() function retrieves the auxiliary info vector requested in aux. The information is stored into the provided buffer if it will fit. The following values, defined in <sys/elf_common.h> can be requested (corresponding buffer sizes are specified in parenthesis): AT_CANARY The canary value for SSP (arbitrary sized buffer, as many bytes are returned as it fits into it, rest is zeroed). AT_EXECPATH The path of executed program (MAXPATHLEN). This may not be present if the process was initialized by fexecve(2) and the namecache no longer contains the file's name. AT_HWCAP CPU / hardware feature flags (sizeof(u_long)). AT_HWCAP2 CPU / hardware feature flags (sizeof(u_long)). AT_NCPUS Number of CPUs (sizeof(int)). AT_OSRELDATE The OSRELDATE of the kernel or jail the program is running on (sizeof(int)). AT_PAGESIZES Vector of page sizes (arbitrary sized buffer, as many elements of the pagesizes array are returned as it fits). AT_PAGESZ Page size in bytes (sizeof(int)). AT_TIMEKEEP Pointer to VDSO timehands (for library internal use, sizeof(void *)). AT_USRSTACKBASE Top of the user stack for main thread. AT_USRSTACKLIM Limit for grow of the user stack for main thread. RETURN VALUES Returns zero on success, or an error number on failure. ERRORS [EINVAL] An unknown item was requested. [EINVAL] The provided buffer was not the right size for the requested item. Only a small subset of available auxiliary info vector items are accessible with this function. Some items require a "right-sized" buffer while others just require a "big enough" buffer. FreeBSD 14.0-RELEASE-p11 September 16, 2022 FreeBSD 14.0-RELEASE-p11