Open System Services Shell and Utilities Reference Manual (G06.29+, H06.08+, J06.03+)

sh(1) OSS Shell and Utilities Reference Manual
2. When the shell encounters the >> characters, it does not open the file in append mode;
instead, the shell opens the file for writing and seeks to the end.
3. Failure (nonzero exit status) of a special command preceding a || symbol prevents the list
following || from executing.
4. If a command that is a tracked alias is executed, and then a command with the same
name is installed in a directory in the search path before the directory where the original
command was found, the shell continues to exec the original command. Use the -t flag
of the alias command to correct this situation.
5. Using the fc built-in command within a compound command causes the whole command
to disappear from the history file.
6. The built-in .file command reads the whole file before any commands are executed.
Therefore, the alias and unalias commands in the file do not apply to any functions
defined in the file.
7. Traps are not processed while a job is waiting for a foreground process. Thus, a trap on
CHLD is not executed until the foreground job terminates.
8. The shell displays the following progress message if it needs to retry the fork operation
during an attempt at process creation:
sh: Resource temporarily unavailable....
will retry fork() for MAX 62 secs...
If the indicated time passes before the fork operation is successful, the shell returns the
following message:
/bin/-sh: sh: tdm_fork() failed with errno EAGAIN:
cannot fork too many processes
EXIT VALUES
Errors detected by the shell, such as syntax errors, cause the shell to return a nonzero exit status.
Otherwise, the shell returns the exit status of the last command executed. (See also the exit com-
mand, described previously.) If the shell is being used noninteractively, execution of the shell
file is abandoned. Run-time errors detected by the shell are reported by printing the command or
function name and the error condition. If the line number that the error occurred on is greater
than 1, the line number is also printed in [](brackets) after the command or function name.
RELATED INFORMATION
Commands: cd(1), chmod(1), echo(1), env(1), ksh(1), setacl(1), stty(1), test(1), umask(1),
vi(1).
Functions: exec(2), fcntl(2), fork(2), ioctl(2), lseek(2), pipe(2), rand(3), umask(2), ulimit(3),
wait(2).
Files: locale(4).
Miscellaneous topics: acl(5).
STANDARDS CONFORMANCE
The following commands are HP extensions to the shell built-in commands of the XPG4 Vewr-
sion 2 specification. They are described in detail in their own reference pages:
add_define
Creates DEFINEs for the Guardian environment.
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