2009年11月23日 · Everywhere in the literature, references to "POSIX compliance" pop up, and the typical definition of POSIX people find is "a set of standards for interoperability among Unix-like operating systems". Although useful, this definition leaves a lot of doubts, specially regarding the features that are expected to interoperate.

POSIX first was a standard in 1988 long before the Single UNIX Specification. It was one of the attempts at unifying all the various UNIX forks and UNIX-like systems. POSIX is an IEEE Standard, but as the IEEE does not own the UNIX® trademark, the standard is not UNIX® though it is based on the existing UNIX API at that time.

2013年6月1日 · The POSIX.1c definition of a reentrant function does not imply thread-safety since a function may be reentrant, thread-safe, both or neither. A reentrant function guarantees only that invocations do not interfere with each other by modifying state that other invocations depend on, not that those invocations are necessarily thread-safe.

2024年12月17日 · POSIX defines a text file as "a file that contains characters organized into zero or more lines". However, according to POSIX definition of a line, there are two possible "kinds" of text files with zero lines: an empty file; a non-empty file consisting solely of a single incomplete line (a line with at least one character and no \n).

2024年1月7日 · My understanding is: POSIX storage refers to any storage that can be accessed using POSIX filesystem functions (ie. the usual 'fopen'), and that complies with POSIX filesystem requirements: this means that it must provide several facilities like POSIX attributes, or atomic file-blocking strictly following POSIX semantics.

2015年10月14日 · In online manual page netdevice(7) - Linux man page, the definition of ifreq structure is given as:. struct ifreq { char ifr_name[IFNAMSIZ]; /* Interface name */ union { struct sockaddr ifr_addr; struct sockaddr ifr_dstaddr; struct sockaddr ifr_broadaddr; struct sockaddr ifr_netmask; struct sockaddr ifr_hwaddr; short ifr_flags; int ifr_ifindex; int ifr_metric; int ifr_mtu; …

2016年3月8日 · POSIX spec did not specify any way to dump function definition, nor how functions are implemented. In bash , you don't have to export the function to the environment, you can use: declare -f funcname

2010年8月19日 · Note that on Linux, CLOCK_MONOTONIC does not measure time spent in suspend, although by the POSIX definition it should. You can use the Linux-specific CLOCK_BOOTTIME for a monotonic clock that keeps running during suspend.

2015年1月25日 · Given the posix definition, I would expect cp -R srcDir existingDestDir to result in the contents of srcDir to be copied into the existingDestDir. Instead srcDir gets copied into existingDestDir both in bash and csh implementations of sh. The relevant portion of the posix cp -R definition: For each source_file, the following steps shall be ...

2009年4月8日 · POSIX's definition of "text line" is relevant as a term they can refer to within the standard e.g. wc -l will not count the last incomplete line. But whether it aspire to regulate semantics or not, doesn't matter much; a very important quality of UNIX I/O is that it's not record-oriented, it's just a flat sequence of 8-bit octets — any ...