.\"* coprocess: exec extensions for coprocesing
.\" 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 coprocess 3 2014-05-27 "VirtualSquare" "Linux Programmer's Manual"
.SH NAME

coprocv, coprocvp, coprocvpe, coprocs, coprocsp \- execute a command in coprocessing mode
.SH SYNOPSIS
.B #include <execs.h>
.sp
.BI "pid_t coprocv(const char *" path ", char *const " argv "[], int " pipefd "[2]);"
.br
.BI "pid_t coprocve(const char *" path ", char *const " argv "[],"
.br
.BI "                           char *const " envp "[], int " pipefd "[2]);"
.br
.BI "pid_t coprocvp(const char *" file ", char *const " argv "[], int " pipefd "[2]);
.br
.BI "pid_t coprocvpe(const char *" file ", char *const " argv "[],"
.br
.BI "                           char *const " envp "[], int " pipefd "[2]);
.sp
.BI "pid_t coprocs(const char *" path ", const char *" command ", int " pipefd "[2]);
.br
.BI "pid_t coprocse(const char *" path ", const char *" command ","
.br
.BI "                           char *const " envp "[], int " pipefd "[2]);
.br
.BI "pid_t coprocsp(const char *" command ", int " pipefd "[2]);
.br
.BI "pid_t coprocspe(const char *" command ", char *const " envp "[],"
.br
.BI "                           int " pipefd "[2]);
.sp
These functions are provided by libexecs. Link with \fI-lexecs\fR.
.SH DESCRIPTION
These functions run commands in coprocessing mode. 
They differs in the way to specify the executable file to run and its 
parameters. 
All of them define two pipes (by \fBpipe\fR(2)), create a new process by 
\fBfork\fR(2), redirect the standard input and output of the new process 
in the two pipes, and exec a program by one of the \fBexec\fR(3) functions.
.sp
The calling program controls both the standard input and the standard output
of the called process: writing to \fBpipefd[1]\fR provides input to the
coprocess while the coprocess output can be retrieved from \fBpipefd[0]\fR.
.sp
\fBcoprocv\fR,
\fBcoprocve\fR,
\fBcoprocvp\fR,
\fBcoprocvpe\fR,
\fBcoprocs\fR,
\fBcoprocse\fR,
\fBcoprocsp\fR,
and \fBcoprocsp\fR
differ as they define the executable file to run and its arguments as
\fBexecv\fR,
\fBexecve\fR,
\fBexecvp\fR,
\fBexecvpe\fR,
\fBexecs\fR,
\fBexecse\fR,
\fBexecsp\fR,
and \fBexecsp\fR, repectively.

.SH BUGS
Bug reports should be addressed to <info@virtualsquare.org>
.SH AUTHOR
Renzo Davoli <renzo@cs.unibo.it>