FBB::StdExtractor - Runs external programs writing standard error

       Frank B. Brokken (f.b.brokken@rug.nl).

libbobcat-dev_6.07.01                               2005-2025                         FBB::StdExtractor(3bobcat)

       Bobcat is an acronym of `Brokken’s Own Base Classes And Templates’.

       o      https://fbb-git.gitlab.io/bobcat/: gitlab project page;

       Debian Bobcat project files:

       o      libbobcat6: debian package containing the shared library, changelog and copyright note;

       o      libbobcat-dev:  debian package containing the static library, headers, manual pages, and developer
              info;

       None reported.

       o      StdExtractor(size_tbufSize=100):
              A  bufSize  argument  may  be  specified:  it  defines  the  internal  buffer  size  used  by  the
              StdExtractor’s streambuf. By default the stdandard input  stream is not handled.

       o      CoutExtractor(Modemode,size_tbufSize=100):
              The  mode argument must be StdExtractor::CLOSE_STD. It indicates that the standard input stream is
              redirected to /dev/null: the child processes cannot read their standard input streams.  A  bufSize
              argument  may  be  specified:  it  defines  the  internal  buffer  size  used by the CinInserter’s
              streambuf.

       Copy and move constructors (and assignment operators) are not available.

       This is free software, distributed under the terms of the GNU General Public License (GPL).

       The  FBB::StdExtractor  class  offers  a  basic  interface for calling external programs (so-called childprocesses) writing their standard output and error streams.  The  standard  input  stream  of  the  child
       processes  are  by  default not handled by StdExtractor objects. The child’s standard output and standard
       error streams are read through the StdExtractor object: information written by the child process to these
       streams is extracted or read from StdExtractor object. The PATH environment variable  is  not  used  when
       calling child processes: child process programs must be specified using paths.

       StdExtractor 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 content 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 @).

       #include <iostream>

       #include <bobcat/cerrextractor>

       using namespace std;
       using namespace FBB;

       int main()
       {
           CerrExtractor 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’;

       }

bobcat/cerrextractor - provides the class interface

FBB::Exec (private), FBB::IFdBuf (private), std::istream

       o      voidexecute(std::stringconst&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 and standard error streams may be extracted
              from the StdExtractor 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.

       o      intret()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.

       FBB::StdExtractor - Runs external programs writing standard error

FBB
       All  constructors,  members,  operators  and manipulators, mentioned in this man-page, are defined in the
       namespace FBB.

       o      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
              error output into the pipe.

bobcat(7), cerrextractor(3bobcat), cininserter(3bobcat), coutextractor(3bobcat), execl(3), exec(3bobcat),
       fork(3bobcat), process(3bobcat).

#include<bobcat/cerrextractor>
       Linking option: -lbobcat