FBB::CoutExtractor(3bobcat)
Executing Child Processes
(libbobcat-dev_4.08.03-x.tar.gz)
2005-2018
NAME
FBB::CoutExtractor - Runs external programs writing standard output
SYNOPSIS
    #include <bobcat/coutextractor>
    Linking option: -lbobcat 
DESCRIPTION
    The FBB::CoutExtractor class offers a basic interface for calling
external programs (so-called child processes) writing their standard
output streams. The standard input and standard error streams of the child
processes by default are not handled by ttCoutExtractor) objects. The child's
standard output is read through the CoutExtractor object: information
written by the child process to its standard output stream is extracted or
read from CoutExtractor object. The PATH environment variable is not
used when calling child processes: child process programs must be specified
using paths.
CoutExtractor objects may repeatedly be used to execute the same or
different child processes. 
Arguments passed to child processes may be surrounded by double or single
quotes. Arguments surrounded by double quotes have their double quotes
removed, while interpreting any escape-sequences that may have been used
within. Arguments surrounded by single quotes have their single quotes
removed, while accepting their contents as-is. In addition unquoted
escape-sequences may be specified: those escape sequences are evaluated and
replaced by their intended characters (e.g., \100 is converted to @).
NAMESPACE
    FBB
    All constructors, members, operators and manipulators, mentioned in this
man-page, are defined in the namespace FBB.
INHERITS FROM
    FBB::Exec (private),
    FBB::IFdStreambuf (private),
    std::istream
CONSTRUCTOR
    -  CoutExtractor(size_t bufSize = 100):
 A bufSize argument may be specified: it defines the internal buffer
        size used by the CoutExtractor's streambuf. By default the
        stdandard input and standard error streams are not handled.
-  CoutExtractor(Mode mode, size_t bufSize = 100):
 The mode argument must be CoutExtractor::CLOSE_STD. It
        indicates that the standard input and standard error streams are
        redirected to /dev/null: the child processes cannot read their
        standard input streams and any standard error output generated by
        child processes is ignored. A bufSize argument may be specified:
        it defines the internal buffer size used by the CinInserter's
        streambuf.
MEMBERS
    -  void execute(std::string const &cmd):
 The argument specifies the command to execute: the command itself must
        be specified as a path (the PATH environment variable isn't used).
        This member immediately returns, after which information written by
        the child process to its standard output stream may be extracted from
        the CoutExtractor object.
Once execute has returned it can be called again, either using the
        same or another command. 
 
Arguments passed to the program to be executed as child process may
        optionally be specified using single or double quotes, as described in
        this man-page's DESCRIPTION section.
 
 
-  int ret() const:
 Once execute has returned this member provides the actual exit
code of the child process. Its value equals -1 before the first exectue
call.
PROTECTED MEMBER
    -  Pipe &childOutPipe():
 If derived classes need to override the redirections-members then they
        probabaly need access to the pipe written by the child process. This
        member provides a reference to that pipe. By default the parent
        process reads information from the pipe, while the child process
        inserts its standard output into the pipe.
EXAMPLE
#include <iostream>
#include <bobcat/coutextractor>
using namespace std;
using namespace FBB;
int main()
{
    CoutExtractor extractor;
    extractor.execute("/bin/cat driver.cc");
    cout << extractor.rdbuf();
    cerr << "Returning: " << extractor.ret() << "\n"
            "again:\n";
    extractor.execute("/bin/cat driver.cc");
    cout << extractor.rdbuf();
    cerr << "Returning: " << extractor.ret() << '\n';
}
FILES
    bobcat/coutextractor - provides the class interface
SEE ALSO
 
    bobcat(7), cerrextractor(3bobcat), cininserter(3bobcat),
    execl(3), exec(3bobcat), 
    fork(3bobcat), process(3bobcat), stdextractor(3bobcat).
BUGS
    None reported.
DISTRIBUTION FILES
    
    -  bobcat_4.08.03-x.dsc: detached signature;
    
-  bobcat_4.08.03-x.tar.gz: source archive;
    
-  bobcat_4.08.03-x_i386.changes: change log;
    
-  libbobcat1_4.08.03-x_*.deb: debian package holding the
            libraries;
    
-  libbobcat1-dev_4.08.03-x_*.deb: debian package holding the
            libraries, headers and manual pages;
    
-  http://sourceforge.net/projects/bobcat: public archive location;
    
BOBCAT
    Bobcat is an acronym of `Brokken's Own Base Classes And Templates'.
COPYRIGHT
    This is free software, distributed under the terms of the 
    GNU General Public License (GPL).
AUTHOR
    Frank B. Brokken (f.b.brokken@rug.nl).