cpython/Python/sysmodule.c

/***********************************************************
Copyright 1991, 1992 by Stichting Mathematisch Centrum, Amsterdam, The
Netherlands.

                        All Rights Reserved

Permission to use, copy, modify, and distribute this software and its 
documentation for any purpose and without fee is hereby granted, 
provided that the above copyright notice appear in all copies and that
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distribution of the software without specific, written prior permission.

STICHTING MATHEMATISCH CENTRUM DISCLAIMS ALL WARRANTIES WITH REGARD TO
THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
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WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

******************************************************************/

/* System module */

/*
Various bits of information used by the interpreter are collected in
module 'sys'.
Function member:
- exit(sts): call (C, POSIX) exit(sts)
Data members:
- stdin, stdout, stderr: standard file objects
- modules: the table of modules (dictionary)
- path: module search path (list of strings)
- argv: script arguments (list of strings)
- ps1, ps2: optional primary and secondary prompts (strings)
*/

#include "allobjects.h"

#include "sysmodule.h"
#include "import.h"
#include "modsupport.h"
#include "osdefs.h"

object *sys_trace, *sys_profile;

static object *sysdict;

object *
sysget(name)
	char *name;
{
	return dictlookup(sysdict, name);
}

FILE *
sysgetfile(name, def)
	char *name;
	FILE *def;
{
	FILE *fp = NULL;
	object *v = sysget(name);
	if (v != NULL)
		fp = getfilefile(v);
	if (fp == NULL)
		fp = def;
	return fp;
}

int
sysset(name, v)
	char *name;
	object *v;
{
	if (v == NULL) {
		if (dictlookup(sysdict, name) == NULL)
			return 0;
		else
			return dictremove(sysdict, name);
	}
	else
		return dictinsert(sysdict, name, v);
}

static object *
sys_exit(self, args)
	object *self;
	object *args;
{
	/* Raise SystemExit so callers may catch it or clean up. */
	err_setval(SystemExit, args);
	return NULL;
}

static object *
sys_settrace(self, args)
	object *self;
	object *args;
{
	if (args == None)
		args = NULL;
	else
		XINCREF(args);
	XDECREF(sys_trace);
	sys_trace = args;
	INCREF(None);
	return None;
}

static object *
sys_setprofile(self, args)
	object *self;
	object *args;
{
	if (args == None)
		args = NULL;
	else
		XINCREF(args);
	XDECREF(sys_profile);
	sys_profile = args;
	INCREF(None);
	return None;
}

static struct methodlist sys_methods[] = {
	{"exit",	sys_exit},
	{"setprofile",	sys_setprofile},
	{"settrace",	sys_settrace},
	{NULL,		NULL}		/* sentinel */
};

static object *sysin, *sysout, *syserr;

void
initsys()
{
	extern int fclose PROTO((FILE *));
	extern char version[];
	object *v = newstringobject(version);
	object *m = initmodule("sys", sys_methods);
	sysdict = getmoduledict(m);
	INCREF(sysdict);
	/* NB keep an extra ref to the std files to avoid closing them
	   when the user deletes them */
	sysin = newopenfileobject(stdin, "<stdin>", "r", fclose);
	sysout = newopenfileobject(stdout, "<stdout>", "w", fclose);
	syserr = newopenfileobject(stderr, "<stderr>", "w", fclose);
	if (err_occurred())
		fatal("can't create sys.* objects");
	dictinsert(sysdict, "stdin", sysin);
	dictinsert(sysdict, "stdout", sysout);
	dictinsert(sysdict, "stderr", syserr);
	dictinsert(sysdict, "version", v);
	dictinsert(sysdict, "modules", get_modules());
	if (err_occurred())
		fatal("can't insert sys.* objects in sys dict");
	DECREF(v);
}

static object *
makepathobject(path, delim)
	char *path;
	int delim;
{
	int i, n;
	char *p;
	object *v, *w;
	
	n = 1;
	p = path;
	while ((p = strchr(p, delim)) != NULL) {
		n++;
		p++;
	}
	v = newlistobject(n);
	if (v == NULL)
		return NULL;
	for (i = 0; ; i++) {
		p = strchr(path, delim);
		if (p == NULL)
			p = strchr(path, '\0'); /* End of string */
		w = newsizedstringobject(path, (int) (p - path));
		if (w == NULL) {
			DECREF(v);
			return NULL;
		}
		setlistitem(v, i, w);
		if (*p == '\0')
			break;
		path = p+1;
	}
	return v;
}

void
setpythonpath(path)
	char *path;
{
	object *v;
	if ((v = makepathobject(path, DELIM)) == NULL)
		fatal("can't create sys.path");
	if (sysset("path", v) != 0)
		fatal("can't assign sys.path");
	DECREF(v);
}

static object *
makeargvobject(argc, argv)
	int argc;
	char **argv;
{
	object *av;
	if (argc <= 0 || argv == NULL) {
		/* Ensure at least one (empty) argument is seen */
		static char *empty_argv[1] = {""};
		argv = empty_argv;
		argc = 1;
	}
	av = newlistobject(argc);
	if (av != NULL) {
		int i;
		for (i = 0; i < argc; i++) {
			object *v = newstringobject(argv[i]);
			if (v == NULL) {
				DECREF(av);
				av = NULL;
				break;
			}
			setlistitem(av, i, v);
		}
	}
	return av;
}

void
setpythonargv(argc, argv)
	int argc;
	char **argv;
{
	object *av = makeargvobject(argc, argv);
	if (av == NULL)
		fatal("no mem for sys.argv");
	if (sysset("argv", av) != 0)
		fatal("can't assign sys.argv");
	DECREF(av);
}