---
name: "msg"
section: "3bobcat"
platform: "linux"
package: "libbobcat-dev"
version: "2.08.01-1"
release: "Debian 6.0 (Squeeze)"
platforms: ["linux"]
url: "https://new.carta.tech/msg"
---

# msg(3bobcat)

Generic message handler

## NAME

FBB::Msg - Generic message handler

## SYNOPSIS

**#include \<bobcat/msg\>**\
 Linking option: *-lbobcat*

## DESCRIPTION

## NAMESPACE

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

## INHERITS FROM

\-

## CONSTRUCTORS

The class **Msg** only has static members. There are no constructors.

## MEMBER FUNCTIONS

The class **Msg** only has static members. The member functions listed below are not frequently used. They exist primarily to control the output streams and to fine-tune the inner workings of the class’ data members. Instead, the class-less members **msg()** and **lineMsg()** (see below) and the manipulators (see below) are used to create messages.

- o

  **static size\_t count()**:\
   Returns the number of error messages generated so far.

- o

  **static bool display()**:\
   Returns *true* if the currently accumulated message will be inserted into the message stream. This is the default case.

- o

  **static size\_t errors()**:\
   Returns the number of error messages generated so far. Synonym of **count()**.

- o

  **static std::streambuf \*infoToWarning()**:\
   Following this call all \`info’-messages will be written to the same stream as warning messages. The function returns the **streambuf** used so far.

- o

  **static void open(std::ifstream &in, std::string const &name)**:\
   Convenience function opening the object *ifstream in* refers to. If opening the stream fails, a fatal error message is generated.

- o

  **static void open(std::ofstream &out, std::string const &name)**:\
   Convenience function opening (creating) the object *ofstream out* refers to. If opening the stream fails, a fatal error message is generated.

- o

  **static void open(std::ofstream &out, std::string const &name, size\_t** **protection)**:\
   Convenience function opening (creating) the object *ofstream out* refers to. The protection value is normally specified as an octal value. From the [**chmod**(1)](/chmod/1.md) manpage:

-

  The  mode is from one to  four  octal  digits  (0-7),  derived  by adding up the bits with values 4, 2, and 1.  Omitted digits are assumed to be leading zeros.  The first digit selects the set user ID  (4)  and set group ID (2) and restricted deletion or sticky (1) attributes.  The second digit selects permissions for the user who owns the  file:  read (4),  write  (2),  and  execute  (1); the third selects permissions for other users in the file’s group, with the same values; and  the  fourth for other users not in the file’s group, with the same values.

-

  If opening the stream fails, a fatal error message is generated.

- o

  **static bool setDisplay(bool mode)**:\
   Changes the setting of the \`display’ variable. At **true** (Note that the default is **false**) accumulated messages will be inserted into the message stream.

- o

  **static std::streambuf \*setInfoBuf(std::streambuf \*newBuffer,** **bool display = true)**:\
   Define a new **streambuf** into which info-messages will be inserted. The passed **streambuf** must remain in existence after the call. If **newBuffer** is 0, the currently used **streambuf** is not altered. The function returns the **streambuf** used so far.

- o

  **static void setLine(size\_t linenr)**:\
   Set the value of the line-counter used with the **lineMsg** manipulator (see below).

- o

  **static void setMaxCount(size\_t maxCount)**:\
   Define the maximum number of error messages (using the **err** manipulator, see below), before a fatal *maximum number of error messsages* *reached* message is generated. The default value is the maximum size\_t value; not reached in any practical situation.

- o

  **static void setOstream(std::string const &name)**:\
   Define the name of the stream to which messages will be written.

- o

  **static void setWarning(char const \*pre = "\[Warning\] ")**:\
   Define the text printed ahead of warning messages. The default value is equal to this member function’s default argument value.

- o

  **static size\_t warnings()**:\
   Returns the number of warning messages generated so far.

## FREE FUNCTIONS

Note that the following two functions are not members of the class **Msg**, but *are* defined in the namespace **FBB**.

- o

  **std::ostringstream &linMsg()**:\
   Information inserted into this function is used to compose a message. Messages must be completed, using an appropriate manipulator, before another message can be constructed. The final message is prefixed by the text \`*Line \<nr\>:* ’, where *\<nr\>* is the value last set by the member function **setLine()**. Note the blank trailing the colon.

- o

  **std::ostringstream &msg()**:\
   Information inserted into this function is used to compose a message. Messages must be completed, using an appropriate manipulator, before another message can be constructed.

- o

  **std::ostringstream &msgstream()**:\
   Contrary to the function **msg**, which will first clear the current contents of the message buffer, **msgstream** returns the current stream \`as is’. This allows the use of certain Template Library algorithms, like *copy*. E.g., assuming that *std::vector\<std::string\> d\_words* has been defined, and using directives were specificied for the *std* and *FBB* namespaces, then

  ```
      copy(d_words.begin(), d_words.end(), ostream_iterator<string>(msg, " "));
      msgstream() << info;
  ```

  can be used to insert the contents of *d\_words*, separated by a blank space, into the *Msg* stream.

## MANIPULATORS

The following manipulators (which are *not* part of the **FBB::Msg**, class, but *are* defined in the **FBB** namespace) can be inserted into the **FBB::Msg** object. All messages are by default inserted into the standard output stream (*cout*).

- o

  **FBB::err**:\
   An error message is generated. Error messages are prefixed by the text \`*\[Error \<count\>\]* ’, where *\<count\>* counts the number of error messages generated so far. If the maximum error count is exceeded (see **setMaxCount()** above) a fatal message is generated as well. A newline is added to the message by the manipulator.

- o

  **FBB::fatal**:\
   A fatal message is generated. Fatal messages are prefixed by the text \`*\[Fatal\]* ’. Following a fatal message an **Errno(1)** exception is thrown.  A newline is added to the message by the manipulator.

- o

  **FBB::info**:\
   This manipulator generates an informational message. Information messages may be controlled by the **setDisplay()** member (see above), and have no further characteristics.  A newline is added to the message by the manipulator.

- o

  **FBB::spool**:\
   This manipulator generates a (partial) informational message.  **spool** does not add a newline message, but merrely flushes the stream’s buffer.

- o

  **FBB::warning**:\
   This manipulator generates a warning message. Warning messages may be controlled by the **setDisplay()** member (see above). By default the text \`*\[Warning\]* ’ is prefixed to the message, but the prefixed message is configurable.  A newline is added to the message by the manipulator.

## OVERLOADED OPERATOR

The following insertion operator is *not* defined in the namespace **FBB** but in *std*. It is part of the distribution to allow the manipulators to be inserted into an **ostrstream**:

- o

  **void operator\<\<(ostream &ostrstream, void (\*)(ostream &))**:\
   The second argument normally is one of the manipulators defined above.

## EXAMPLE

```
    #include <bobcat/msg>
    using namespace FBB;
    int main(int argc)
    try
    {
        if (argc == 1)
            msg() << "Need some arguments" << fatal;
        else
        {
            Msg::setDisplay(true);
            msg() << "Thanks for providing " << argc <<
                                    " arguments " << info;
        }
    }
    catch(...)
    {
        msg() << "Got an Errno object, but ignoring it" << err;
    }
```

## FILES

*bobcat/msg* - defines the class interface

## SEE ALSO

[**bobcat**(7)](/bobcat/7.md), [**errno**(3bobcat)](/errno/3bobcat.md), [**indent**(3bobcat)](/indent/3bobcat.md)

## BUGS

None Reported.

## DISTRIBUTION FILES

- o

  *bobcat\_2.08.01-x.dsc*: detached signature;

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  *bobcat\_2.08.01-x.tar.gz*: source archive;

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  *bobcat\_2.08.01-x\_i386.changes*: change log;

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  *libbobcat1\_2.08.01-x\_\*.deb*: debian package holding the libraries;

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  *libbobcat1-dev\_2.08.01-x\_\*.deb*: debian package holding the libraries, headers and manual pages;

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  *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**).