cc [ flag ... ] file ... -lnsl [ library ... ]
# include <sac.h>
int doconfig(int fildes, char *script, long rflag);
Unsafe
script is the name of the configuration script; fildes is a file descriptor that designates the stream to which stream manipulation operations are to be applied; rflag is a bitmask that indicates the mode in which script is to be interpreted. If rflag is zero, all commands in the configuration script are eligible to be interpreted. If rflag has the NOASSIGN bit set, the assign command is considered illegal and will generate an error return. If rflag has the NORUN bit set, the run and runwait commands are considered illegal and will generate error returns.
The configuration language in which script is written consists of a sequence of commands, each of which is interpreted separately. The following reserved keywords are defined: assign, push, pop, runwait, and run. The comment character is #; when a # occurs on a line, everything from that point to the end of the line is ignored. Blank lines are not significant. No line in a command script may exceed 1024 characters.
assign variable=value
Used to define environment variables. variable is the name of the environment
variable and value is the value to be assigned to it. The value assigned
must be a string constant; no form of parameter substitution is available.
value may be quoted. The quoting rules are those used by the shell for defining
environment variables. assign will fail if space cannot be allocated for
the new variable or if any part of the specification is invalid.
push module1[,
module2, module3, . . .]
Used to push STREAMS
modules onto the stream designated by fildes. module1
is the name of the first module to be pushed, module2 is the name of the
second module to be pushed, etc. The command will fail if any of the named
modules cannot be pushed. If a module cannot be pushed, the subsequent modules
on the same command line will be ignored and modules that have already
been pushed will be popped.
pop [module]
Used to pop STREAMS
modules off the designated stream. If pop is invoked
with no arguments, the top module on the stream is popped. If an argument
is given, modules will be popped one at a time until the named module is
at the top of the stream. If the named module is not on the designated stream,
the stream is left as it was and the command fails. If module is the special
keyword ALL
, then all modules on the stream will be popped. Note that only
modules above the topmost driver are affected.
runwait command
The runwait command runs a command and waits for it to complete. command
is the pathname of the command to be run. The command is run with /usr/bin/sh
-c prepended to it; shell scripts may thus be executed from configuration
scripts. The runwait command will fail if command cannot be found or cannot
be executed, or if command exits with a non-zero status.
run command
The run command is identical to runwait except that it does not wait for
command to complete. command is the pathname of the command to be run. run
will not fail unless it is unable to create a child process to execute
the command.
Although they are syntactically indistinguishable, some of the commands available to run and runwait are interpreter built-in commands. Interpreter built-ins are used when it is necessary to alter the state of a process within the context of that process. The doconfig() interpreter built-in commands are similar to the shell special commands and, like these, they do not spawn another process for execution. See sh(1) . The built-in commands are:
cd ulimit umask