UCommon
Data Structures | Public Types | Public Member Functions | Static Public Member Functions
ucc::shell Class Reference

A utility class for generic shell operations. More...

#include <shell.h>

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Data Structures

class  charopt
 Character option for shell parsing. More...
class  counteropt
 Counter option for shell parsing. More...
class  errormap
 A class to redefine error messages. More...
class  flagopt
 Flag option for shell parsing. More...
class  groupopt
 Grouping option. More...
class  iobuf
 Process pipe with I/O buffering. More...
class  numericopt
 Numeric option for shell parsing. More...
class  Option
 A base class used to create parsable shell options. More...
class  pipeio
 A class to control a process that is piped. More...
class  stringopt
 Text option for shell parsing. More...

Public Types

typedef void(* downproc_t )(bool reload)
 Shutdown handler.
enum  errmsg_t {
  NOARGS = 0, NOARGUMENT, INVARGUMENT, BADOPTION,
  OPTION_USED, BAD_VALUE
}
 Error table index.
typedef iobuf io_t
 Buffered i/o type for pipes and stdio.
enum  loglevel_t {
  FAIL = 0, ERR, WARN, NOTIFY,
  INFO, DEBUG0
}
 Level of error logging.
enum  logmode_t { NONE = 0, CONSOLE_LOG, USER_LOG, SYSTEM_LOG }
 Type of error logging we are using.
typedef bool(* logproc_t )(loglevel_t level, const char *text)
 Log process handler.
typedef int pid_t
 Standard type of process id for shell class.
typedef pipeiopipe_t
 Convenience low level pipe object type.
enum  pmode_t { RD = BufferProtocol::BUF_RD, WR = BufferProtocol::BUF_WR, RDWR = BufferProtocol::BUF_RDWR }
 Pipe I/O mode.

Public Member Functions

unsigned argc (void) const
 Get saved internal argc count for items.
char ** argv (void) const
 Get saved internal argv count for items in this shell object.
const char * argv0 () const
 Get program name (argv0).
void detach (downproc_t stopreload=(downproc_t) NULL)
 Detach current process to daemon.
char ** getargv (char **argv)
 Get the argument list by parsing options, and return the remaining file arguments.
char * getargv0 (char **argv)
 Parse and extract the argv0 filename alone.
const char * getenv (const char *name, const char *value=NULL)
 Get an environment variable.
const char * getsym (const char *name, const char *value=NULL)
 Get a local symbol.
bool issym (const char *name)
 Test if symbol exists.
unsigned operator() (void)
 Return argc count.
const char * operator[] (unsigned offset)
 Return parser argv element.
void parse (int argc, char **argv)
 Parse the command line arguments using the option table.
char ** parse (const char *string)
 Parse a string as a series of arguments for use in exec calls.
void restart (void)
 Make current process restartable.
void restart (char *argv0, char **argv, char **list)
 Execute front-end like gdb based on stripped first argument.
void setsym (const char *name, const char *value)
 Set a local symbol.
 shell (const char *string, size_t pagesize=0)
 Construct a shell argument list by parsing a simple command string.
 shell (size_t pagesize=0)
 Construct an empty shell parser argument list.
 shell (int argc, char **argv, size_t pagesize=0)
 Construct a shell argument list from existing arguments.
void up (void)
 Notify service is up.

Static Public Member Functions

static void bind (const char *name)
 Bind application to text domain for internationalization.
static int cancel (shell::pid_t pid)
 Cancel a child process.
static int cancel (shell::pipe_t pointer)
 Cancel a child pipe.
static unsigned count (char **argv)
 Get argc count for an existing array.
static void debug (unsigned level, const char *format,...)
 Print a debug message by debug level.
static int detach (const char *path, char **argv, char **env=NULL, fd_t *stdio=NULL)
 Create a detached process.
static void errexit (int exitcode, const char *format=NULL,...)
 Print error message and exit.
static void errmsg (errmsg_t id, const char *text)
 This is used to set internationalized error messages for the shell parser.
static const char * errmsg (errmsg_t id)
 This can be used to get internationalized error messages.
static fd_t error (void)
static void help (void)
 Display shell options.
static fd_t input (void)
static void log (loglevel_t level, const char *format,...)
 Print error message at specific error level.
static void log (const char *name, loglevel_t level=ERR, logmode_t mode=USER_LOG, logproc_t handler=(logproc_t) NULL)
 Set logging level and state.
static fd_t output (void)
static char ** parse (shell &args, const char *string)
 Parse shell arguments directly into a shell object.
static size_t printf (const char *format,...)
 Print to standard output.
static size_t printf (pipe_t pipe, const char *format,...)
 Print to a pipe object.
static void priority (int pri=1)
 Set priority level and enable priority scheduler.
static size_t read (String &string)
static size_t read (pipe_t pipe, String &string)
static size_t readln (pipe_t pipe, char *buffer, size_t size)
 Read a line from a pipe object.
static size_t readln (char *address, size_t size)
static void rebind (const char *name=NULL)
 Rebind is used to change the text domain.
static shell::pid_t spawn (const char *path, char **argv, char **env=NULL, fd_t *stdio=NULL)
 Spawn a child process.
static shell::pipe_t spawn (const char *path, char **argv, pmode_t mode, size_t size=512, char **env=NULL)
 Spawn a child pipe.
static int system (const char *command, const char **env=NULL)
 A shell system call.
static int systemf (const char *format,...)
 A shell system call that can be issued using a formatted string.
static const char * text (const char *string)
 Text translation and localization.
static const char * texts (const char *singular, const char *plural, unsigned long count)
 Plural text translation and localization.
static int wait (shell::pipe_t pointer)
 Wait for a child pipe to terminate.
static int wait (shell::pid_t pid)
 Wait for a child process to terminate.
static size_t write (pipe_t pipe, String &string)
static size_t write (String &string)
static size_t writes (const char *string)
static size_t writes (pipe_t pipe, const char *string)

Detailed Description

A utility class for generic shell operations.

This includes utilities to parse and expand arguments, and to call system shell services. This also includes a common shell class to parse and process command line arguments which are managed through a local heap.

Author:
David Sugar <dyfet@gnutelephony.org>

Definition at line 58 of file shell.h.


Constructor & Destructor Documentation

ucc::shell::shell ( const char *  string,
size_t  pagesize = 0 
)

Construct a shell argument list by parsing a simple command string.

This separates a string into a list of command line arguments which can be used with exec functions.

Parameters:
stringto parse.
pagesizefor local heap.
ucc::shell::shell ( int  argc,
char **  argv,
size_t  pagesize = 0 
)

Construct a shell argument list from existing arguments.

This copies and on some platforms expands the argument list originally passed to main.

Parameters:
argcfrom main.
argvfrom main.
pagesizefor local heap.
ucc::shell::shell ( size_t  pagesize = 0)

Construct an empty shell parser argument list.

Parameters:
pagesizefor local heap.

Member Function Documentation

unsigned ucc::shell::argc ( void  ) const [inline]

Get saved internal argc count for items.

This may be items that remain after shell expansion and options have been parsed.

Returns:
count of remaining arguments.

Definition at line 784 of file shell.h.

char** ucc::shell::argv ( void  ) const [inline]

Get saved internal argv count for items in this shell object.

This may be filename items only that remain after shell expansion and options that have been parsed.

Returns:
list of remaining arguments.

Definition at line 793 of file shell.h.

static void ucc::shell::bind ( const char *  name) [static]

Bind application to text domain for internationalization.

This is useful if the argv0 argument can vary because of a symlinked executable. This is the name of the .po/.mo message files for your application. If bind is not called before shell processing, then the argv0 is used as the bind name. Bind can be called multiple times to change the default message catalog name of the application, and this usage may be needed for plugins, though it's generally recommended to use only once, and at the start of main().

Parameters:
nameof text domain for the application.
static int ucc::shell::cancel ( shell::pid_t  pid) [static]

Cancel a child process.

Parameters:
pidof child process to cancel.
Returns:
exit code of process, -1 if fails or pid is invalid.
static int ucc::shell::cancel ( shell::pipe_t  pointer) [static]

Cancel a child pipe.

If the pipe io handle is dynamic, it is deleted.

Parameters:
pointerto pipe of child process to cancel.
Returns:
exit code of process, -1 if fails or pid is invalid.
static unsigned ucc::shell::count ( char **  argv) [static]

Get argc count for an existing array.

Parameters:
argvto count items in.
Returns:
argc count of array.
static void ucc::shell::debug ( unsigned  level,
const char *  format,
  ... 
) [static]

Print a debug message by debug level.

Parameters:
levelof debug message.
formatstring to use.
static int ucc::shell::detach ( const char *  path,
char **  argv,
char **  env = NULL,
fd_t *  stdio = NULL 
) [static]

Create a detached process.

This creates a new child process that is completely detached from the current process.

Parameters:
pathto executable.
argvlist of command arguments for the child process.
envof child process can be explicitly set.
stdiohandles for stdin, stdout, and stderr.
Returns:
0 if success, -1 on error.
static void ucc::shell::errexit ( int  exitcode,
const char *  format = NULL,
  ... 
) [static]

Print error message and exit.

Parameters:
exitcodeto return to parent process.
formatstring to use.
static void ucc::shell::errmsg ( errmsg_t  id,
const char *  text 
) [static]

This is used to set internationalized error messages for the shell parser.

Parameters:
idof message to set.
textfor error message.
static const char* ucc::shell::errmsg ( errmsg_t  id) [static]

This can be used to get internationalized error messages.

The internal text for shell parser errors are passed through here.

Parameters:
idof error message to use.
Returns:
published text of error message.
char** ucc::shell::getargv ( char **  argv)

Get the argument list by parsing options, and return the remaining file arguments.

This is used by parse, and can be fed by main by posting ++argv.

Parameters:
argvof first option.
Returns:
argv of non-option file list.
char* ucc::shell::getargv0 ( char **  argv)

Parse and extract the argv0 filename alone.

Parameters:
argvfrom main.
Returns:
argv0 simple path name.
const char* ucc::shell::getenv ( const char *  name,
const char *  value = NULL 
)

Get an environment variable.

This creates a local copy of the variable in pager memory.

Parameters:
nameof symbol.
valueof symbol if not found.
Returns:
value of symbol.
const char* ucc::shell::getsym ( const char *  name,
const char *  value = NULL 
)

Get a local symbol.

This uses getenv if no local symbol is found.

Parameters:
nameof symbol.
valueof symbol if not found.
Returns:
value of symbol.
bool ucc::shell::issym ( const char *  name)

Test if symbol exists.

Parameters:
nameof symbol.
Returns:
true if found.
static void ucc::shell::log ( loglevel_t  level,
const char *  format,
  ... 
) [static]

Print error message at specific error level.

Parameters:
levelof error condition.
formatstring to use.
static void ucc::shell::log ( const char *  name,
loglevel_t  level = ERR,
logmode_t  mode = USER_LOG,
logproc_t  handler = (logproc_t) NULL 
) [static]

Set logging level and state.

Parameters:
nameof logging entity.
levelof error conditions to log.
modeof logging.
handlerfor log messages.
unsigned ucc::shell::operator() ( void  ) [inline]

Return argc count.

Returns:
argc count.

Definition at line 894 of file shell.h.

const char* ucc::shell::operator[] ( unsigned  offset) [inline]

Return parser argv element.

Parameters:
offsetinto array.
Returns:
argument string.

Definition at line 801 of file shell.h.

static char** ucc::shell::parse ( shell args,
const char *  string 
) [inline, static]

Parse shell arguments directly into a shell object.

Parameters:
argstable.
stringto parse.
Returns:
argument array.

Definition at line 701 of file shell.h.

void ucc::shell::parse ( int  argc,
char **  argv 
)

Parse the command line arguments using the option table.

File arguments will be expanded for wildcards on some platforms. The argv will be set to the first file argument after all options are parsed.

Parameters:
argcfrom main.
argvfrom main.
char** ucc::shell::parse ( const char *  string)

Parse a string as a series of arguments for use in exec calls.

Parameters:
stringto parse.
Returns:
argument array.
static size_t ucc::shell::printf ( const char *  format,
  ... 
) [static]

Print to standard output.

Parameters:
formatstring to use.
static size_t ucc::shell::printf ( pipe_t  pipe,
const char *  format,
  ... 
) [static]

Print to a pipe object.

Parameters:
pipeto write to.
formatstring to use.
Returns:
number of bytes written.
static void ucc::shell::priority ( int  pri = 1) [static]

Set priority level and enable priority scheduler.

This activates the realtime priority scheduler when a priority > 0 is requested for the process, assuming scheduler support exists and the process is sufficiently privileged. Negative priorities are essentially the same as nice.

Parameters:
prilevel for process.
static size_t ucc::shell::readln ( pipe_t  pipe,
char *  buffer,
size_t  size 
) [static]

Read a line from a pipe object.

Parameters:
pipeto read from.
bufferto save into.
sizeof buffer.
Returns:
number of bytes read.
static void ucc::shell::rebind ( const char *  name = NULL) [static]

Rebind is used to change the text domain.

This may be needed in applications which have separately built plugins that have thier own message catalogs. Normally the plugin would call bind itself at initialization, and then use rebind to select either the application's domain, or the plugins. On systems without internationalization, this has no effect.

Parameters:
nameof text domain of plugin or NULL to restore application.
void ucc::shell::restart ( char *  argv0,
char **  argv,
char **  list 
)

Execute front-end like gdb based on stripped first argument.

Parameters:
argv0of our executable.
argvto pass to child.
listof arguments to execute in front of argv.
void ucc::shell::setsym ( const char *  name,
const char *  value 
)

Set a local symbol.

Parameters:
nameof symbol to set.
valueof symbol to set.
static shell::pipe_t ucc::shell::spawn ( const char *  path,
char **  argv,
pmode_t  mode,
size_t  size = 512,
char **  env = NULL 
) [static]

Spawn a child pipe.

If the executable path is a pure filename, then the $PATH will be used to find it. The argv array may be created from a string with the shell string parser.

Parameters:
pathto executable.
argvlist of command arguments for the child process.
modeof pipe, rd only, wr only, or rdwr.
sizeof pipe buffer.
envof child process can be explicitly set.
Returns:
pipe object or NULL on failure.
static shell::pid_t ucc::shell::spawn ( const char *  path,
char **  argv,
char **  env = NULL,
fd_t *  stdio = NULL 
) [static]

Spawn a child process.

This creates a new child process. If the executable path is a pure filename, then the $PATH will be used to find it. The argv array may be created from a string with the shell string parser.

Parameters:
pathto executable.
argvlist of command arguments for the child process.
envof child process can be explicitly set.
stdiohandles for stdin, stdout, and stderr.
Returns:
process id of child or INVALID_PID_VALUE if fails.
static int ucc::shell::system ( const char *  command,
const char **  env = NULL 
) [static]

A shell system call.

This uses the native system shell to invoke the command.

Parameters:
commandstring..
envarray to optionally use.
Returns:
error code of child process.
static int ucc::shell::systemf ( const char *  format,
  ... 
) [static]

A shell system call that can be issued using a formatted string.

This uses the native system shell to invoke the command.

Parameters:
formatof/command string.
Returns:
error code of child process.
static const char* ucc::shell::text ( const char *  string) [static]

Text translation and localization.

This function does nothing but return the original string if no internationalization support is available. If internationalization support exists, then it may return a substituted translation based on the current locale. This offers a single function that can be safely used either when internationalization support is present, or it is absent, eliminating the need for the application to be coded differently based on awareness of support.

Parameters:
stringto translate.
Returns:
translation if found or original text.
static const char* ucc::shell::texts ( const char *  singular,
const char *  plural,
unsigned long  count 
) [static]

Plural text translation and localization.

This does nothing but return single or plural forms if no internationalization is enabled. Else it uses ngettext().

Parameters:
singularstring to translate.
pluralstring to translate.
countof objects.
Returns:
string to use.
static int ucc::shell::wait ( shell::pipe_t  pointer) [static]

Wait for a child pipe to terminate.

This operation blocks. If the pipe io handle is dynamic, it is deleted.

Parameters:
pointerto pipe of child process to wait for.
Returns:
exit code of process, -1 if fails or pid is invalid.
static int ucc::shell::wait ( shell::pid_t  pid) [static]

Wait for a child process to terminate.

This operation blocks.

Parameters:
pidof process to wait for.
Returns:
exit code of process, -1 if fails or pid is invalid.

The documentation for this class was generated from the following file: