.\"* esystem: system replacement not using any shell (iversion for embedded systems)
.\" Copyright (C) 2014 Renzo Davoli. University of Bologna. <renzo@cs.unibo.it>
.\" 
.\" This library is free software; you can redistribute it and/or
.\" modify it under the terms of the GNU Lesser General Public
.\" License as published by the Free Software Foundation; either
.\" version 2.1 of the License, or (at your option) any later version.
.\" 
.\" This library is distributed in the hope that it will be useful,
.\" but WITHOUT ANY WARRANTY; without even the implied warranty of
.\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
.\" Lesser General Public License for more details.
.\" 
.\" You should have received a copy of the GNU Lesser General Public
.\" License along with this library; if not, write to the Free Software
.\" Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
.TH system_nosh 3 2014-05-27 "VirtualSquare" "Linux Programmer's Manual"
.SH NAME

esystem, system_eexecsp \- execute a command with its arguments from a string without using a shell
.SH SYNOPSIS
.B #include <stdlib.h>
.br
.B #include <execs.h>
.sp
.BI "int esystem(const char *" command ");"
.br
.BI "int system_eexecsp(const char *" command ");"
.sp
These functions are provided by libexecs and libeexecs. Link with \fI-lexecs\fR or \fI-leexecs\fR.
.SH DESCRIPTION
\fBesystem\fR is an almost drop in replacement for \fBsystem\fR(3)
provided by the libc. \fBesystem\fR parses the command string
and runs the command directly, without using a shell.
(\fBsystem_eexecsp\fR and \fBesystem\fR are synonyms).
.br
Command arguments in \fIargs\fR are delimited by space characters (blank, tabs
or new lines).
Single or double quotes can be used to delimitate command arguments including
spaces and a non quoted backslash (\fB\e\fP)
is the escape character to protect the next char. The executable file
is sought using the PATH environment variable as explained for \fBexeclp\fR(3).
.br
.SH RETURN VALUE
These functions have the same return values of \fBsystem\fR(3). 
.SH EXAMPLE
The following program shows the usage of \fBesystem\fR:
.BR
.sp
\&
.nf
#include <stdio.h>
#include <unistd.h>
#include <execs.h>

#define BUFLEN 1024
int main(int argc, char *argv)
{
	char buf[BUFLEN];
	printf("type in a command and its arguments, e.g. 'ls -l'\\n");
	while (fgets(buf, BUFLEN, stdin) != NULL) {
		printf("Command: '%s' \\n",buf);
		esystem(buf);
		printf("Command done\\n");
	}
}
.fi
.SH SEE ALSO
.BR system (3), execs (3), s2argv(3), system_nosh(3)
.SH BUGS
Bug reports should be addressed to <info@virtualsquare.org>
.SH AUTHOR
Renzo Davoli <renzo@cs.unibo.it>