Features Introduced Past 1979
Over the years, the Bourne shell was enhanced at AT&T. The various variants are thus called like the respective AT&T Unix version it was released with (some important variants being Version7, SystemIII, SVR2, SVR3, SVR4). As the shell was never versioned, the only way to identify it was testing its features.
Features of the Bourne shell versions since 1979 include:
- Built-in test command – System III shell (1981)
- # as comment character – System III shell (1981)
- Colon in parameter substitutions "${parameter:=word}" – System III shell (1981)
- Functions and the return builtin – SVR2 shell (1984)
- Built-ins unset, echo, type – SVR2 shell (1984)
- Source code de-ALGOL68-ized – SVR2 shell (1984)
- Modern "$@" – SVR3 shell (1986)
- Built-in getopts – SVR3 shell (1986)
- Cleaned up parameter handling allows recursively callable functions – SVR3 shell (1986)
- 8-bit clean – SVR3 shell (1986)
- Job control – SVR4 shell (1989)
- Multi-byte support – SVR4 shell (1989)
Read more about this topic: Bourne Shell
Famous quotes containing the words features and/or introduced:
“The features of our face are hardly more than gestures which force of habit made permanent. Nature, like the destruction of Pompeii, like the metamorphosis of a nymph into a tree, has arrested us in an accustomed movement.”
—Marcel Proust (1871–1922)
“Those who first introduced compulsory education into American life knew exactly why children should go to school and learn to read: to save their souls.... Consistent with this goal, the first book written and printed for children in America was titled Spiritual Milk for Boston Babes in either England, drawn from the Breasts of both Testaments for their Souls’ Nourishment.”
—Dorothy H. Cohen (20th century)