mini_epn.c

/* 
 *
 *  MINI_EPN.C - Mini Embedded Perl Nagios
 *  Contributed by Stanley Hopcroft
 *  Modified by Douglas Warner
 *  Last Modified: 05/02/2002
 *
 *  This is a sample mini embedded Perl interpreter (hacked out checks.c and 
 *  perlembed) for use in testing Perl plugins. 
 *
 *  It can be compiled with the following command (see 'man perlembed' for 
 *  more info):
 *
 *  gcc -omini_epn mini_epn.c `perl -MExtUtils::Embed -e ccopts -e ldopts`
 *
 *  NOTES:  The compiled binary needs to be in the same directory as the p1.pl
 *  file supplied with Nagios (or vice versa)
 *  When using mini_epn to test perl scripts, you must place positional
 *  arguments immediately after the file/script and before any arguments
 *  processed by Getopt
 *
 */


#include <EXTERN.h>
#include <perl.h>
#include <fcntl.h>
#include <string.h>

/* include PERL xs_init code for module and C library support */

#if defined(__cplusplus)
#define is_cplusplus
#endif

#ifdef is_cplusplus
extern "C" {
#endif

#define NO_XSLOCKS
#include <XSUB.h>

#ifdef is_cplusplus
}
#  ifndef EXTERN_C
#    define EXTERN_C extern "C"
#  endif
#else
#  ifndef EXTERN_C
#    define EXTERN_C extern
#  endif
#endif
 

EXTERN_C void xs_init _((void));

EXTERN_C void boot_DynaLoader _((CV* cv));

EXTERN_C void xs_init(void)
{
	char *file = __FILE__;
	dXSUB_SYS;

	/* DynaLoader is a special case */
	newXS("DynaLoader::boot_DynaLoader", boot_DynaLoader, file);
}


static PerlInterpreter *perl = NULL;


int main(int argc, char **argv, char **env)
{
	char *embedding[] = { "", "p1.pl" };
	char plugin_output[1024];
	char buffer[512];
	char tmpfname[32];
	char fname[32];
	char *args[] = {"","0", "", "", NULL };
	FILE *fp;

	const int command_line_size = 160;
	char command_line[command_line_size];
	char *ap ;
	int exitstatus;
	int pclose_result;
#ifdef THREADEDPERL
	dTHX;
#endif
	dSP; 

	if ((perl=perl_alloc())==NULL) {
		snprintf(buffer,sizeof(buffer),"Error: Could not allocate memory for embedded Perl interpreter!\n");
		buffer[sizeof(buffer)-1]='\x0';
		printf("%s\n", buffer);
		exit(1);
	}
	perl_construct(perl);
	exitstatus=perl_parse(perl,xs_init,2,embedding,NULL);
	if (!exitstatus) {

		exitstatus=perl_run(perl);

		while(printf("Enter file name: ") && fgets(command_line, command_line_size, stdin)) {

			/* call the subroutine, passing it the filename as an argument */

			command_line[strlen(command_line) -1] = '\0';

			strncpy(fname,command_line,strcspn(command_line," "));
			fname[strcspn(command_line," ")] = '\x0';
			args[0] = fname ;
			args[3] = command_line + strlen(fname) + 1 ;

			/* generate a temporary filename to which stdout can be redirected. */
			sprintf(tmpfname,"/tmp/embedded%d",getpid());
			args[2] = tmpfname;

			/* call our perl interpreter to compile and optionally cache the command */
			perl_call_argv("Embed::Persistent::eval_file", G_DISCARD | G_EVAL, args);

			perl_call_argv("Embed::Persistent::run_package", G_DISCARD | G_EVAL, args);
			
			/* check return status  */
			if(SvTRUE(ERRSV)){
				pclose_result=-2;
				printf("embedded perl ran %s with error %s\n",fname,SvPV(ERRSV,PL_na));
			}
			
			/* read back stdout from script */
			fp=fopen(tmpfname, "r");
			
			/* default return string in case nothing was returned */
			strcpy(plugin_output,"(No output!)");
			
			fgets(plugin_output,sizeof(plugin_output)-1,fp);
			plugin_output[sizeof(plugin_output)-1]='\x0';
			fclose(fp);
			unlink(tmpfname);    
			printf("embedded perl plugin output was %d,%s\n",pclose_result, plugin_output);

		}

	}

	
	PL_perl_destruct_level = 0;
	perl_destruct(perl);
	perl_free(perl);
	exit(exitstatus);
}