Section 5.10. Grouping Commands

[Page 179 (continued)]

5.10. Grouping Commands

Commands may be grouped by placing them between parentheses, which causes them to be executed by a child shell (subshell). The group of commands shares the same standard input, standard output, and standard error channels, and may be redirected and piped as if it were a simple command. Here are some examples:

$ date; ls; pwd > out.txt           ...execute a sequence Wed Feb  2 00:33:12 CST 2005        ...output from date. 
[Page 180]a.c       b.c                       ...output from ls. $ cat out.txt                       ...only pwd was redirected. /home/glass $ (date; ls; pwd) > out.txt         ...group and then redirect. $ cat out.txt                       ...all output was redirected. Wed Feb  2 00:33:28 CST 2005 a.c b.c /home/glass $ _