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//*****************************************************************************
//
//! @file am_util_cmdline.c
//!
//! @brief Functions to implement a simple command line interface.
//!
//! Functions supporting a command-line interface.
//
//*****************************************************************************
//*****************************************************************************
//
// Copyright (c) 2017, Ambiq Micro
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// 3. Neither the name of the copyright holder nor the names of its
// contributors may be used to endorse or promote products derived from this
// software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
// This is part of revision v1.2.10-2-gea660ad-hotfix2 of the AmbiqSuite Development Package.
//
//*****************************************************************************
#include <stdint.h>
#include <stdbool.h>
#include "am_util_cmdline.h"
#include "am_util_string.h"
//*****************************************************************************
//
// Macro definitions
//
//*****************************************************************************
//
// Note - the UART Instance should actually be specified by the BSP.
//
#define CMDLINE_UART_INST 0
#define MAX_CMDLINE_ARGS 10
//*****************************************************************************
//
// Interface parameter structure
//
//*****************************************************************************
am_util_cmdline_interface_t *g_psInterface;
//*****************************************************************************
//
// Character parsing state information.
//
//*****************************************************************************
uint32_t g_ui32BufferIndex = 0;
bool g_bQuoted = 0;
bool g_bEscaped = 0;
bool g_bPromptNeeded = 0;
//*****************************************************************************
//
// Command execution data.
//
//*****************************************************************************
char *g_ppcArgs[MAX_CMDLINE_ARGS];
uint32_t g_ui32Argc = 0;
//*****************************************************************************
//
//! @brief Initialize the command line.
//!
//! @param psInterface is a pointer to an interface structure defining key
//! characteristics about the command line interface.
//!
//! This function may be used to initialize a command prompt for user
//! interaction. Please see the documentation on am_util_cmdline_interface_t
//! for more details on command line configuration.
//!
//! @note This function must be the first cmdline function to be called in the
//! final application.
//!
//! @return None.
//
//*****************************************************************************
void
am_util_cmdline_init(am_util_cmdline_interface_t *psInterface)
{
g_psInterface = psInterface;
g_bQuoted = false;
g_bEscaped = false;
g_bPromptNeeded = true;
g_ui32BufferIndex = 0;
g_ppcArgs[0] = psInterface->psCommandData;
g_ui32Argc = 0;
}
//*****************************************************************************
//
// Parses characters as they come in through the interface. If the return value
// is true, there is a command to execute.
//
//*****************************************************************************
bool
parse_char(char cChar)
{
//
// Check the state variables to figure out the correct interpretation of
// this character.
//
if ( cChar == 0x7F || cChar == 0x08 || cChar == '\f' )
{
//
// First, if the character was a backspace or delete, clear out
// everything and return.
//
g_bQuoted = false;
g_bEscaped = false;
g_ui32BufferIndex = 0;
g_psInterface->psCommandData[0] = 0;
g_ppcArgs[0] = g_psInterface->psCommandData;
g_ui32Argc = 0;
}
else if ( g_bEscaped )
{
//
// If we're currently in an 'escape' sequence, print whatever character
// comes next, no matter what.
//
g_psInterface->psCommandData[g_ui32BufferIndex] = cChar;
g_ui32BufferIndex++;
g_bEscaped = false;
}
else if ( g_bQuoted )
{
//
// If we're in a quoted context, look out for end quotes, and
// backslashes. Everything else is handled as-is.
//
if ( cChar == '"' )
{
g_bQuoted = false;
}
else if ( cChar == '\\' )
{
g_bEscaped = true;
}
else
{
g_psInterface->psCommandData[g_ui32BufferIndex] = cChar;
g_ui32BufferIndex++;
}
}
else
{
//
// If we're not in any special context, all characters retain their
// special meanings.
//
if ( cChar == '"' )
{
g_bQuoted = true;
}
else if ( cChar == '\\' )
{
g_bEscaped = true;
}
else if ( cChar == ' ' )
{
//
// Spaces delimit arguments, so we need to replace them with NULL
// terminators.
//
g_psInterface->psCommandData[g_ui32BufferIndex] = 0;
g_ui32BufferIndex++;
//
// Also adjust the argument lists as appropriate
//
g_ui32Argc++;
g_ppcArgs[g_ui32Argc] = g_psInterface->psCommandData + g_ui32BufferIndex;
}
else if ( cChar == '\n' || cChar == '\r' )
{
//
// New lines delimit entire commands, so we need to replace them
// with NULL terminators.
//
g_psInterface->psCommandData[g_ui32BufferIndex] = 0;
g_ui32BufferIndex++;
//
// Also adjust the argument lists as appropriate.
//
g_ui32Argc++;
return true;
}
else
{
//
// If none of the other cases caught this character, it should just
// be copied into the command buffer as is.
//
g_psInterface->psCommandData[g_ui32BufferIndex] = cChar;
g_ui32BufferIndex++;
}
}
//
// Make sure we're not about to overflow the command buffer. If we are,
// just end the function here, and report "true" in hopes that the command
// can be identified.
//
if ( g_ui32BufferIndex > g_psInterface->ui32CommandDataLen )
{
return true;
}
//
// Also make sure to check the maximum number of arguments to make sure
// this buffer doesn't overflow either.
//
if ( g_ui32Argc >= MAX_CMDLINE_ARGS )
{
return true;
}
//
// If we haven't returned by this point, this character can be assumed not
// to be the last character of a command.
//
return false;
}
//*****************************************************************************
//
// Simple function for printing the prompt string.
//
//*****************************************************************************
void
print_prompt(void)
{
char *pcChar;
pcChar = g_psInterface->pcPromptString;
while ( *pcChar )
{
g_psInterface->pfnPutChar(CMDLINE_UART_INST, *pcChar);
pcChar++;
}
}
//*****************************************************************************
//
// Echoes characters back to the user interface as they are received. Certain
// characters are handled differently.
//
//*****************************************************************************
void
echo_char(char cChar)
{
//
// If there isn't an output function, just return.
//
if ( !g_psInterface->pfnPutChar )
{
return;
}
switch(cChar)
{
case '\r':
case '\n':
g_psInterface->pfnPutChar(CMDLINE_UART_INST, '\r');
g_psInterface->pfnPutChar(CMDLINE_UART_INST, '\n');
break;
case 0x7F:
case 0x08:
//
// Erase the line.
//
g_psInterface->pfnPutChar(CMDLINE_UART_INST, '\033');
g_psInterface->pfnPutChar(CMDLINE_UART_INST, '[');
g_psInterface->pfnPutChar(CMDLINE_UART_INST, '2');
g_psInterface->pfnPutChar(CMDLINE_UART_INST, 'K');
g_psInterface->pfnPutChar(CMDLINE_UART_INST, '\r');
//
// Print the prompt.
//
print_prompt();
break;
case '\033':
g_psInterface->pfnPutChar(CMDLINE_UART_INST, '\\');
g_psInterface->pfnPutChar(CMDLINE_UART_INST, 'e');
break;
case '\f':
g_psInterface->pfnPutChar(CMDLINE_UART_INST, '\f');
//
// Print the prompt.
//
print_prompt();
break;
default:
g_psInterface->pfnPutChar(CMDLINE_UART_INST, cChar);
}
}
//*****************************************************************************
//
//! @brief Execute a command by name.
//!
//! @param args is an array of strings that make up the arguments of the
//! command.
//!
//! @param argc is the number of argument strings contained in args
//!
//! This function performs a lookup in the command table to find a function
//! whose command string matches the value of args[0]. If it finds a match, it
//! will run the function, passing along args and argc as its arguments. When
//! the inner function returns, the return code will be passed back up to the
//! caller.
//!
//! @return Returns the same value as the command function that was called, or
//! a -1 if the command could not be found.
//
//*****************************************************************************
uint32_t
am_util_cmdline_run_command(char **args, uint32_t argc)
{
am_util_cmdline_command_t *psCommands;
uint32_t ui32Index, ui32NumCommands, ui32CommandDataLen;
char *pcCommand;
//
// Grab a few important parameters from the global structure.
//
psCommands = g_psInterface->psCommandList;
ui32NumCommands = g_psInterface->ui32NumCommands;
ui32CommandDataLen = g_psInterface->ui32CommandDataLen;
//
// Loop over the commands in the global table.
//
for ( ui32Index = 0; ui32Index < ui32NumCommands; ui32Index++ )
{
//
// Check the command name against the first argument.
//
pcCommand = psCommands[ui32Index].pcCommand;
if ( !am_util_string_strncmp(pcCommand, args[0], ui32CommandDataLen) )
{
//
// If the command matches the argument, run the command and return.
//
return psCommands[ui32Index].pfnCommand(args, argc);
}
}
//
// Return a negative one to indicate that there was no command found.
//
return 0xffffffff;
}
//*****************************************************************************
//
//! @brief Look for and process any incoming commands.
//!
//! This function should be called periodically to check for commands on the
//! user interface. Each call will read characters from the interface until it
//! either completes an entire command, or the provided pfnGetChar() function
//! returns an error. Echoing characters back to the user interface will be
//! handled by this function unless the pfnPutChar() function was not provided.
//!
//! @return None.
//
//*****************************************************************************
void
am_util_cmdline_process_commands(void)
{
char cChar = {0};
//
// If we need to print a prompt, do it now.
//
if ( g_bPromptNeeded )
{
print_prompt();
g_bPromptNeeded = false;
}
//
// As long as there are characters to get, keep reading them.
//
while ( g_psInterface->pfnGetChar(&cChar) == 0 )
{
//
// Echo the character back to the interface.
//
echo_char(cChar);
//
// Run the parser to see if this char completed a command.
//
if ( parse_char(cChar) )
{
//
// If a command is ready to go, run it now. This function call will
// return the return code of the command function that it calls. This
// may be used in later implementations for error-checking and
// error-reporting.
//
am_util_cmdline_run_command(g_ppcArgs, g_ui32Argc);
//
// Reset the state variables to prepare for the next command.
//
g_bQuoted = false;
g_bEscaped = false;
g_bPromptNeeded = true;
g_ui32BufferIndex = 0;
g_psInterface->psCommandData[0] = 0;
g_ppcArgs[0] = g_psInterface->psCommandData;
g_ui32Argc = 0;
return;
}
}
}