exec.c File Reference

Command execution. More...

#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>
#include <unistd.h>
#include <getopt.h>
#include <errno.h>
#include <assert.h>
#include <ipxe/tables.h>
#include <ipxe/command.h>
#include <ipxe/parseopt.h>
#include <ipxe/settings.h>
#include <ipxe/shell.h>

Go to the source code of this file.

Data Structures
struct	echo_options
	"echo" options More...
struct	exit_options
	"exit" options More...
struct	isset_options
	"isset" options More...
struct	iseq_options
	"iseq" options More...
struct	sleep_options
	"sleep" options More...

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
int	execv (const char *command, char *const argv[])
	Execute command. More...
static int	split_command (char *command, char **tokens)
	Split command line into tokens. More...
static int	process_on_success (int rc)
	Process next command only if previous command succeeded. More...
static int	process_on_failure (int rc)
	Process next command only if previous command failed. More...
static int	process_always (int rc __unused)
	Process next command regardless of status from previous command. More...
static int	command_terminator (char **tokens, int(**process_next)(int rc))
	Find command terminator. More...
void	shell_stop (int stop)
	Set shell stop state. More...
int	shell_stopped (int stop)
	Test and consume shell stop state. More...
static int	expand_tokens (int argc, char **tokens, char **argv)
	Expand settings within a token list. More...
static void	free_tokens (char **argv)
	Free an expanded token list. More...
int	system (const char *command)
	Execute command line. More...
char *	concat_args (char **args)
	Concatenate arguments. More...
static int	echo_exec (int argc, char **argv)
	"echo" command More...
static int	exit_exec (int argc, char **argv)
	"exit" command More...
static int	isset_exec (int argc, char **argv)
	"isset" command More...
static int	iseq_exec (int argc, char **argv)
	"iseq" command More...
static int	sleep_exec (int argc, char **argv)
	"sleep" command More...

Variables
static int	stop_state
	Shell stop state. More...
static struct option_descriptor	echo_opts []
	"echo" option list More...
static struct command_descriptor	echo_cmd
	"echo" command descriptor More...
struct command echo_command	__command
	"echo" command More...
static struct option_descriptor	exit_opts [] = {}
	"exit" option list More...
static struct command_descriptor	exit_cmd
	"exit" command descriptor More...
static struct option_descriptor	isset_opts [] = {}
	"isset" option list More...
static struct command_descriptor	isset_cmd
	"isset" command descriptor More...
static struct option_descriptor	iseq_opts [] = {}
	"iseq" option list More...
static struct command_descriptor	iseq_cmd
	"iseq" command descriptor More...
static struct option_descriptor	sleep_opts [] = {}
	"sleep" option list More...
static struct command_descriptor	sleep_cmd
	"sleep" command descriptor More...

Detailed Description

Command execution.

Definition in file exec.c.

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

execv()

int execv	(	const char *	command,
		char *const	argv[]
	)

Execute command.

Parameters

command	Command name
argv	Argument list

Return values

rc	Return status code

Execute the named command. Unlike a traditional POSIX execv(), this function returns the exit status of the command.

Definition at line 60 of file exec.c.

                                                       {
        struct command *cmd;
        int argc;
        int rc;

        /* Count number of arguments */
        for ( argc = 0 ; argv[argc] ; argc++ ) {}

        /* An empty command is deemed to do nothing, successfully */
        if ( command == NULL ) {
                rc = 0;
                goto done;
        }

        /* Sanity checks */
        if ( argc == 0 ) {
                DBG ( "%s: empty argument list\n", command );
                rc = -EINVAL;
                goto done;
        }

        /* Reset getopt() library ready for use by the command.  This
         * is an artefact of the POSIX getopt() API within the context
         * of Etherboot; see the documentation for reset_getopt() for
         * details.
         */
        reset_getopt();

        /* Hand off to command implementation */
        for_each_table_entry ( cmd, COMMANDS ) {
                if ( strcmp ( command, cmd->name ) == 0 ) {
                        rc = cmd->exec ( argc, ( char ** ) argv );
                        goto done;
                }
        }

        printf ( "%s: command not found\n", command );
        rc = -ENOEXEC;

 done:
        /* Store error number, if an error occurred */
        if ( rc ) {
                errno = rc;
                if ( errno < 0 )
                        errno = -errno;
        }

        return rc;
}

References cmd, COMMANDS, DBG, done, EINVAL, ENOEXEC, errno, for_each_table_entry, NULL, printf(), rc, reset_getopt(), and strcmp().

Referenced by system(), and time_exec().

split_command()

static int split_command ( char *  command, char **  tokens  )

static

Split command line into tokens.

Parameters

command	Command line
tokens	Token list to populate, or NULL

Return values

count

Number of tokens

Splits the command line into whitespace-delimited tokens. If tokens is non-NULL, any whitespace in the command line will be replaced with NULs.

Definition at line 121 of file exec.c.

                                                          {
        int count = 0;

        while ( 1 ) {
                /* Skip over any whitespace / convert to NUL */
                while ( isspace ( *command ) ) {
                        if ( tokens )
                                *command = '\0';
                        command++;
                }
                /* Check for end of line */
                if ( ! *command )
                        break;
                /* We have found the start of the next argument */
                if ( tokens )
                        tokens[count] = command;
                count++;
                /* Skip to start of next whitespace, if any */
                while ( *command && ! isspace ( *command ) ) {
                        command++;
                }
        }
        return count;
}

References command, count, and isspace().

Referenced by system().

process_on_success()

static int process_on_success ( int  rc )

static

Process next command only if previous command succeeded.

Parameters

rc	Status of previous command

Return values

process

Process next command

Definition at line 152 of file exec.c.

                                         {
        return ( rc == 0 );
}

References rc.

Referenced by command_terminator().

process_on_failure()

static int process_on_failure ( int  rc )

static

Process next command only if previous command failed.

Parameters

rc	Status of previous command

Return values

process

Process next command

Definition at line 162 of file exec.c.

                                         {
        return ( rc != 0 );
}

References rc.

Referenced by command_terminator().

process_always()

static int process_always ( int rc  __unused )

static

Process next command regardless of status from previous command.

Parameters

rc	Status of previous command

Return values

process

Process next command

Definition at line 172 of file exec.c.

                                              {
        return 1;
}

Referenced by command_terminator().

command_terminator()

static int command_terminator ( char **  tokens, int(**)(int rc)  process_next  )

static

Find command terminator.

Parameters

tokens

Token list

Return values

process_next	"Should next command be processed?" function
argc	Argument count

Definition at line 183 of file exec.c.

                                                                    {
        unsigned int i;

        /* Find first terminating token */
        for ( i = 0 ; tokens[i] ; i++ ) {
                if ( tokens[i][0] == '#' ) {
                        /* Start of a comment */
                        break;
                } else if ( strcmp ( tokens[i], "||" ) == 0 ) {
                        /* Short-circuit logical OR */
                        *process_next = process_on_failure;
                        return i;
                } else if ( strcmp ( tokens[i], "&&" ) == 0 ) {
                        /* Short-circuit logical AND */
                        *process_next = process_on_success;
                        return i;
                } else if ( strcmp ( tokens[i], ";" ) == 0 ) {
                        /* Process next command unconditionally */
                        *process_next = process_always;
                        return i;
                }
        }

        /* End of token list */
        *process_next = NULL;
        return i;
}

References NULL, process_always(), process_on_failure(), process_on_success(), and strcmp().

Referenced by system().

shell_stop()

void shell_stop

(

int

stop

)

Set shell stop state.

Parameters

stop	Shell stop state

Definition at line 217 of file exec.c.

                             {
        stop_state = stop;
}

References stop_state.

Referenced by exit_exec(), goto_exec(), and imgexec().

shell_stopped()

int shell_stopped

(

int

stop

)

Test and consume shell stop state.

Parameters

stop	Shell stop state to consume
stopped	Shell had been stopped

Definition at line 227 of file exec.c.

                               {
        int stopped;

        /* Test to see if we need to stop */
        stopped = ( stop_state >= stop );

        /* Consume stop state */
        if ( stop_state <= stop )
                stop_state = 0;

        return stopped;
}

References stop_state.

Referenced by shell(), system(), and terminate_on_exit_or_failure().

expand_tokens()

static int expand_tokens ( int  argc, char **  tokens, char **  argv  )

static

Expand settings within a token list.

Parameters

argc	Argument count
tokens	Token list
argv	Argument list to fill in

Return values

rc	Return status code

Definition at line 248 of file exec.c.

                                                                  {
        int i;

        /* Expand each token in turn */
        for ( i = 0 ; i < argc ; i++ ) {
                argv[i] = expand_settings ( tokens[i] );
                if ( ! argv[i] )
                        goto err_expand_settings;
        }

        return 0;

 err_expand_settings:
        assert ( argv[i] == NULL );
        for ( ; i >= 0 ; i-- )
                free ( argv[i] );
        return -ENOMEM;
}

References assert(), ENOMEM, expand_settings(), free, and NULL.

Referenced by system().

free_tokens()

static void free_tokens ( char **  argv )

static

Free an expanded token list.

Parameters

argv	Argument list

Definition at line 272 of file exec.c.

                                        {

        /* Free each expanded argument */
        while ( *argv )
                free ( *(argv++) );
}

References free.

Referenced by system().

system()

int system

(

const char *

command

)

Execute command line.

Parameters

command

Command line

Return values

rc	Return status code

Execute the named command and arguments.

Definition at line 287 of file exec.c.

                                   {
        int count = split_command ( ( char * ) command, NULL );
        char *all_tokens[ count + 1 ];
        int ( * process_next ) ( int rc );
        char *command_copy;
        char **tokens;
        int argc;
        int process;
        int rc = 0;

        /* Create modifiable copy of command */
        command_copy = strdup ( command );
        if ( ! command_copy )
                return -ENOMEM;

        /* Split command into tokens */
        split_command ( command_copy, all_tokens );
        all_tokens[count] = NULL;

        /* Process individual commands */
        process = 1;
        for ( tokens = all_tokens ; ; tokens += ( argc + 1 ) ) {

                /* Find command terminator */
                argc = command_terminator ( tokens, &process_next );

                /* Expand tokens and execute command */
                if ( process ) {
                        char *argv[ argc + 1 ];

                        /* Expand tokens */
                        if ( ( rc = expand_tokens ( argc, tokens, argv ) ) != 0)
                                break;
                        argv[argc] = NULL;

                        /* Execute command */
                        rc = execv ( argv[0], argv );

                        /* Free tokens */
                        free_tokens ( argv );
                }

                /* Stop processing, if applicable */
                if ( shell_stopped ( SHELL_STOP_COMMAND ) )
                        break;

                /* Stop processing if we have reached the end of the
                 * command.
                 */
                if ( ! process_next )
                        break;

                /* Determine whether or not to process next command */
                process = process_next ( rc );
        }

        /* Free modified copy of command */
        free ( command_copy );

        return rc;
}

References command_terminator(), count, ENOMEM, execv(), expand_tokens(), free, free_tokens(), NULL, rc, SHELL_STOP_COMMAND, shell_stopped(), split_command(), and strdup().

concat_args()

char* concat_args

(

char **

args

)

Concatenate arguments.

Parameters

args	Argument list (NULL-terminated)

Return values

string

Concatenated arguments

The returned string is allocated with malloc(). The caller is responsible for eventually free()ing this string.

Definition at line 358 of file exec.c.

                                   {
        char **arg;
        size_t len;
        char *string;
        char *ptr;

        /* Calculate total string length */
        len = 1 /* NUL */;
        for ( arg = args ; *arg ; arg++ )
                len += ( 1 /* possible space */ + strlen ( *arg ) );

        /* Allocate string */
        string = zalloc ( len );
        if ( ! string )
                return NULL;

        /* Populate string */
        ptr = string;
        for ( arg = args ; *arg ; arg++ ) {
                ptr += sprintf ( ptr, "%s%s",
                                 ( ( arg == args ) ? "" : " " ), *arg );
        }
        assert ( ptr < ( string + len ) );

        return string;
}

References assert(), len, NULL, sprintf, string, strlen(), and zalloc().

Referenced by echo_exec(), imgsingle_exec(), item_exec(), menu_exec(), param_exec(), prompt_exec(), and set_value().

echo_exec()

static int echo_exec ( int  argc, char **  argv  )

static

"echo" command

Parameters

argc	Argument count
argv	Argument list

Return values

rc	Return status code

Definition at line 409 of file exec.c.

                                               {
        struct echo_options opts;
        char *text;
        int rc;

        /* Parse options */
        if ( ( rc = parse_options ( argc, argv, &echo_cmd, &opts ) ) != 0 )
                return rc;

        /* Parse text */
        text = concat_args ( &argv[optind] );
        if ( ! text )
                return -ENOMEM;

        /* Print text */
        printf ( "%s%s", text, ( opts.no_newline ? "" : "\n" ) );

        free ( text );
        return 0;
}

References concat_args(), echo_cmd, ENOMEM, free, optind, opts, parse_options(), printf(), and rc.

exit_exec()

static int exit_exec ( int  argc, char **  argv  )

static

"exit" command

Parameters

argc	Argument count
argv	Argument list

Return values

rc	Return status code

Definition at line 453 of file exec.c.

                                               {
        struct exit_options opts;
        unsigned int exit_code = 0;
        int rc;

        /* Parse options */
        if ( ( rc = parse_options ( argc, argv, &exit_cmd, &opts ) ) != 0 )
                return rc;

        /* Parse exit status, if present */
        if ( optind != argc ) {
                if ( ( rc = parse_integer ( argv[optind], &exit_code ) ) != 0 )
                        return rc;
        }

        /* Stop shell processing */
        shell_stop ( SHELL_STOP_COMMAND_SEQUENCE );

        return exit_code;
}

References exit_cmd, optind, opts, parse_integer(), parse_options(), rc, shell_stop(), and SHELL_STOP_COMMAND_SEQUENCE.

isset_exec()

static int isset_exec ( int  argc, char **  argv  )

static

"isset" command

Parameters

argc	Argument count
argv	Argument list

Return values

rc	Return status code

Definition at line 497 of file exec.c.

                                                {
        struct isset_options opts;
        int rc;

        /* Parse options */
        if ( ( rc = parse_options ( argc, argv, &isset_cmd, &opts ) ) != 0 )
                return rc;

        /* Return success iff argument is non-empty */
        return ( argv[optind][0] ? 0 : -ENOENT );
}

References ENOENT, isset_cmd, optind, opts, parse_options(), and rc.

iseq_exec()

static int iseq_exec ( int  argc, char **  argv  )

static

"iseq" command

Parameters

argc	Argument count
argv	Argument list

Return values

rc	Return status code

Definition at line 533 of file exec.c.

                                               {
        struct iseq_options opts;
        int rc;

        /* Parse options */
        if ( ( rc = parse_options ( argc, argv, &iseq_cmd, &opts ) ) != 0 )
                return rc;

        /* Return success iff arguments are equal */
        return ( ( strcmp ( argv[optind], argv[ optind + 1 ] ) == 0 ) ?
                 0 : -ERANGE );
}

References ERANGE, iseq_cmd, optind, opts, parse_options(), rc, and strcmp().

sleep_exec()

static int sleep_exec ( int  argc, char **  argv  )

static

"sleep" command

Parameters

argc	Argument count
argv	Argument list

Return values

rc	Return status code

Definition at line 569 of file exec.c.

                                                {
        struct sleep_options opts;
        unsigned int seconds;
        int rc;

        /* Parse options */
        if ( ( rc = parse_options ( argc, argv, &sleep_cmd, &opts ) ) != 0 )
                return rc;

        /* Parse number of seconds */
        if ( ( rc = parse_integer ( argv[optind], &seconds ) ) != 0 )
                return rc;

        /* Delay for specified number of seconds */
        if ( sleep ( seconds ) != 0 )
                return -ECANCELED;

        return 0;
}

References ECANCELED, optind, opts, parse_integer(), parse_options(), rc, seconds, sleep(), and sleep_cmd.

Variable Documentation

stop_state

int stop_state

static

Shell stop state.

Definition at line 48 of file exec.c.

Referenced by shell_stop(), and shell_stopped().

echo_opts

struct option_descriptor echo_opts[]

static

Initial value:

= {
        OPTION_DESC ( "n", 'n', no_argument,
                      struct echo_options, no_newline, parse_flag ),
}

"echo" option list

Definition at line 392 of file exec.c.

echo_cmd

struct command_descriptor echo_cmd

static

Initial value:

=
        COMMAND_DESC ( struct echo_options, echo_opts, 0, MAX_ARGUMENTS,
                       "[...]" )

"echo" command descriptor

Definition at line 398 of file exec.c.

Referenced by echo_exec().

__command

struct command sleep_command __command

Initial value:

= {
        .name = "echo",
        .exec = echo_exec,
}

"echo" command

"sleep" command

"iseq" command

"isset" command

"exit" command

Definition at line 431 of file exec.c.

exit_opts

struct option_descriptor exit_opts[] = {}

static

"exit" option list

Definition at line 440 of file exec.c.

exit_cmd

struct command_descriptor exit_cmd

static

Initial value:

=
        COMMAND_DESC ( struct exit_options, exit_opts, 0, 1, "[<status>]" )

"exit" command descriptor

Definition at line 443 of file exec.c.

Referenced by exit_exec().

isset_opts

struct option_descriptor isset_opts[] = {}

static

"isset" option list

Definition at line 484 of file exec.c.

isset_cmd

struct command_descriptor isset_cmd

static

Initial value:

=
        COMMAND_DESC ( struct isset_options, isset_opts, 1, 1, "<value>" )

"isset" command descriptor

Definition at line 487 of file exec.c.

Referenced by isset_exec().

iseq_opts

struct option_descriptor iseq_opts[] = {}

static

"iseq" option list

Definition at line 519 of file exec.c.

iseq_cmd

struct command_descriptor iseq_cmd

static

Initial value:

=
        COMMAND_DESC ( struct iseq_options, iseq_opts, 2, 2,
                       "<value1> <value2>" )

"iseq" command descriptor

Definition at line 522 of file exec.c.

Referenced by iseq_exec().

sleep_opts

struct option_descriptor sleep_opts[] = {}

static

"sleep" option list

Definition at line 556 of file exec.c.

sleep_cmd

struct command_descriptor sleep_cmd

static

Initial value:

=
        COMMAND_DESC ( struct sleep_options, sleep_opts, 1, 1, "<seconds>" )

"sleep" command descriptor

Definition at line 559 of file exec.c.

Referenced by sleep_exec().