Second

The second (symbol: s) (abbreviated s or sec) is the base unit of time in the International System of Units (SI). It is qualitatively defined as the second division of the hour by sixty, the first division by sixty being the minute. It is quantitatively defined in terms of a certain number of periods – about 9 billion – of a certain frequency of radiation from the caesium atom: a so-called atomic clock. Seconds may be measured using a mechanical, electric or atomic clock.

Environment variable

Environment variables are a set of dynamic named values that can affect the way running processes will behave on a computer.

They are part of the environment in which a process runs. For example, a running process can query the value of the TEMP environment variable to discover a suitable location to store temporary files, or the HOME or USERPROFILE variable to find the directory structure owned by the user running the process.

They were introduced in their modern form in 1979 with Version 7 Unix, so are included in all Unix operating system flavors and variants from that point onward including Linux and OS X. From PC DOS 2.0 in 1982, all succeeding Microsoft operating systems including Microsoft Windows, and OS/2 also have included them as a feature, although with somewhat different syntax, usage and standard variable names.

Details

In all Unix and Unix-like systems, each process has its own separate set of environment variables. By default, when a process is created, it inherits a duplicate environment of its parent process, except for explicit changes made by the parent when it creates the child. At the API level, these changes must be done between running fork and exec. Alternatively, from command shells such as bash, a user can change environment variables for a particular command invocation by indirectly invoking it via env or using the ENVIRONMENT_VARIABLE=VALUE <command> notation. All Unix operating system flavors, DOS, and Windows have environment variables; however, they do not all use the same variable names. A running program can access the values of environment variables for configuration purposes.

Second wine

Second wine (or second label; in French Second vin) is a term commonly associated with Bordeaux wine to refer to a second label wine made from cuvee not selected for use in the Grand vin or first label. In some cases a third wine or even fourth wine is also produced. Depending on the house winemaking style, individual plots of a vineyard may be selected, often those of the youngest vines, and fermented separately, with the best performing barrels being chosen for the house's top wine and the other barrels being bottled under a separate label and sold for a lower price than the Grand vin.

In less favorable vintages, an estate may choose to release only a second label wine rather than to release a smaller than normal quantity of its Grand vin or a wine that would not be consistent with past vintages under that name. The practice has its roots in the 18th century but became more commercially prominent in the 1980s when consumers discovered these wines as a more affordable way to drink the product of a First growth or classified Bordeaux estate without paying the premium for the estate's label and classification.