added first working option parser for short options

This commit is contained in:
prozessorkern 2020-03-16 22:08:06 +01:00
parent 60c4c7dadd
commit ecc43307af
8 changed files with 459 additions and 15 deletions

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@ -77,6 +77,8 @@ typedef struct
typedef struct typedef struct
{ {
uint32_t offset; /**< current offset of the option parser */ uint32_t offset; /**< current offset of the option parser */
uint32_t nextOffset; /**< offset of the next hunk */
uint32_t len; /**< length of the current hunk */
} shellmatta_opt_t; } shellmatta_opt_t;
/** /**

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@ -22,6 +22,7 @@ SOURCES := src/shellmatta.c \
INCLUDES := api . INCLUDES := api .
UNITTEST_SOURCES := test/unittest/test_main.cpp \ UNITTEST_SOURCES := test/unittest/test_main.cpp \
test/unittest/shellmatta_opt/test_opt_findNextHunk.cpp \
test/unittest/shellmatta_utils/test_utils_writeEcho.cpp \ test/unittest/shellmatta_utils/test_utils_writeEcho.cpp \
test/unittest/shellmatta_utils/test_utils_shellItoa.cpp \ test/unittest/shellmatta_utils/test_utils_shellItoa.cpp \
test/unittest/shellmatta_utils/test_utils_saveCursorPos.cpp \ test/unittest/shellmatta_utils/test_utils_saveCursorPos.cpp \

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@ -22,6 +22,7 @@
#include "shellmatta_history.h" #include "shellmatta_history.h"
#include "shellmatta_utils.h" #include "shellmatta_utils.h"
#include "shellmatta_escape.h" #include "shellmatta_escape.h"
#include "shellmatta_opt.h"
#include <stddef.h> #include <stddef.h>
#include <string.h> #include <string.h>
#include <stdarg.h> #include <stdarg.h>
@ -502,8 +503,8 @@ shellmatta_retCode_t shellmatta_processData(shellmatta_handle_t handle,
{ {
/** -# compare command and alias string and length */ /** -# compare command and alias string and length */
if ( ((0 == strncmp( argumentString, if ( ((0 == strncmp( argumentString,
cmd->cmd, cmd->cmd,
cmdLen)) cmdLen))
&& (cmdLen == strlen(cmd->cmd))) && (cmdLen == strlen(cmd->cmd)))
|| ((NULL != cmd->cmdAlias) || ((NULL != cmd->cmdAlias)
&& ((0 == strncmp( argumentString, && ((0 == strncmp( argumentString,
@ -512,7 +513,7 @@ shellmatta_retCode_t shellmatta_processData(shellmatta_handle_t handle,
&& (cmdLen == strlen(cmd->cmdAlias))))) && (cmdLen == strlen(cmd->cmdAlias)))))
{ {
utils_writeEcho(inst, "\r\n", 2u); utils_writeEcho(inst, "\r\n", 2u);
shellmatta_opt_init(inst, cmdLen + 1u);
cmdExecuted = 1u; cmdExecuted = 1u;
cmd->cmdFct(inst, argumentString, argumentLength); cmd->cmdFct(inst, argumentString, argumentLength);
cmd = NULL; cmd = NULL;

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@ -22,6 +22,151 @@
#include "shellmatta.h" #include "shellmatta.h"
#include <string.h> #include <string.h>
/**
* @brief finds the next parsable hunk of data in the input
* @param[in] inst shellmatta instance
* @return errorcode #SHELLMATTA_OK - new hunk found
* #SHELLMATTA_ERROR - error parsing or end of input
*/
static shellmatta_retCode_t findNextHunk(shellmatta_instance_t *inst)
{
shellmatta_retCode_t ret = SHELLMATTA_ERROR;
uint32_t newOffset = inst->optionParser.nextOffset;
uint32_t exeptionOffset = 0u;
char quotation = '\0'; /* holds the current quotation mark if any */
/*! -# find beginning of next hunk */
while( (newOffset < inst->inputCount)
&& ((' ' == inst->buffer[newOffset])
|| ('\0' == inst->buffer[newOffset])))
{
newOffset ++;
}
inst->optionParser.offset = newOffset;
/*! -# determine length */
while((newOffset < inst->inputCount)
&& (((' ' != inst->buffer[newOffset]) && ('\0' != inst->buffer[newOffset])) || '\0' != quotation))
{
/*! -# check for new quotation */
if((('\'' == inst->buffer[newOffset]) || ('"' == inst->buffer[newOffset])) && (quotation == '\0'))
{
quotation = inst->buffer[newOffset];
exeptionOffset ++;
}
/*! -# check if quotation has ended */
else if(quotation == inst->buffer[newOffset])
{
exeptionOffset ++;
/*! -# check if quotation is excaped */
if('\\' != inst->buffer[newOffset - 1u])
{
quotation = '\0';
}
else
{
inst->buffer[newOffset - exeptionOffset] = inst->buffer[newOffset];
}
}
else
{
/*! -# shift back chars */
if(0u != exeptionOffset)
{
inst->buffer[newOffset - exeptionOffset] = inst->buffer[newOffset];
}
}
newOffset ++;
}
inst->optionParser.nextOffset = newOffset;
inst->optionParser.len = newOffset - inst->optionParser.offset - exeptionOffset;
/*! -# add terminating 0 */
inst->buffer[inst->optionParser.offset + inst->optionParser.len] = '\0';
if((inst->optionParser.offset < inst->inputCount) && (0u != inst->optionParser.len) && ('\0' == quotation))
{
ret = SHELLMATTA_OK;
}
return ret;
}
/**
* @brief peeks the first char of the next hunk
* @param[in] inst shellmatta instance
* @return char first char of next hunk \0 if not existing
*/
static char peekNextHunk(shellmatta_instance_t *inst)
{
uint32_t newOffset = inst->optionParser.nextOffset;
/*! -# find beginning of next hunk */
while( (newOffset < inst->inputCount)
&& ((' ' == inst->buffer[newOffset])
|| ('\0' == inst->buffer[newOffset])))
{
newOffset ++;
}
return inst->buffer[newOffset];
}
/**
* @brief tries to parse the current input hunk and check if this is a configured option
* @param[in] handle shellmatta handle
* @param[in] optionString option string e.g. "cd:e::"
* @param[out] option pointer to store the detected option to
* @param[out] argtype pointer to store the argument string to (can be NULL)
* @return errorcode #SHELLMATTA_OK - option parsable and found in option String
* #SHELLMATTA_ERROR - format error or option unknown
*/
static shellmatta_retCode_t parseShortOpt( shellmatta_instance_t *inst,
char *optionString,
char *option,
shellmatta_opt_argtype_t *argtype)
{
shellmatta_retCode_t ret = SHELLMATTA_ERROR;
char *buffer = &inst->buffer[inst->optionParser.offset];
uint32_t i;
/*! -# check for correct syntax */
if((2u == inst->optionParser.len) && ('-' == buffer[0u]) && ('-' != buffer[1u]) && ('\0' != buffer[1u]))
{
/*! -# search for option character in option string */
for(i = 0u; ('\0' != optionString[i]) && (buffer[1u] != optionString[i]); i ++);
if(buffer[1u] == optionString[i])
{
/*! -# return found option character */
*option = buffer[1u];
ret = SHELLMATTA_OK;
/*! -# check if an argument is required or optional */
if(':' == optionString[i + 1u])
{
*argtype = SHELLMATTA_OPT_ARG_REQUIRED;
if(':' == optionString[i + 2u])
{
*argtype = SHELLMATTA_OPT_ARG_OPTIONAL;
}
}
else
{
*argtype = SHELLMATTA_OPT_ARG_NONE;
}
}
}
else
{
*option = '\0';
}
return ret;
}
/** /**
* @brief scans the current input and parses options in getopt style * @brief scans the current input and parses options in getopt style
* @param[in] handle shellmatta handle * @param[in] handle shellmatta handle
@ -29,6 +174,8 @@
* @param[out] option pointer to store the detected option to * @param[out] option pointer to store the detected option to
* @param[out] argument pointer to store the argument string to (can be NULL) * @param[out] argument pointer to store the argument string to (can be NULL)
* @param[out] argLen pointer to store the argument lengh to (can be NULL) * @param[out] argLen pointer to store the argument lengh to (can be NULL)
* @return errorcode #SHELLMATTA_OK - no error - keep on calling
* #SHELLMATTA_ERROR - error occured - e.g. argument missing
*/ */
shellmatta_retCode_t shellmatta_opt( shellmatta_handle_t handle, shellmatta_retCode_t shellmatta_opt( shellmatta_handle_t handle,
char *optionString, char *optionString,
@ -36,8 +183,9 @@ shellmatta_retCode_t shellmatta_opt( shellmatta_handle_t handle,
char **argument, char **argument,
uint32_t *argLen) uint32_t *argLen)
{ {
shellmatta_retCode_t ret = SHELLMATTA_USE_FAULT; shellmatta_retCode_t ret = SHELLMATTA_USE_FAULT;
shellmatta_instance_t *inst = (shellmatta_instance_t*)handle; shellmatta_instance_t *inst = (shellmatta_instance_t*)handle;
shellmatta_opt_argtype_t argtype = SHELLMATTA_OPT_ARG_NONE;
/** -# check parameters for plausibility */ /** -# check parameters for plausibility */
if( (NULL != inst) if( (NULL != inst)
@ -45,7 +193,52 @@ shellmatta_retCode_t shellmatta_opt( shellmatta_handle_t handle,
&& (NULL != optionString) && (NULL != optionString)
&& (NULL != option)) && (NULL != option))
{ {
*option = '\0';
*argument = NULL;
*argLen = 0u;
ret = findNextHunk(inst);
if(SHELLMATTA_OK == ret)
{
ret = parseShortOpt(inst, optionString, option, &argtype);
/*! -# when no option is found return this as raw argument */
if(SHELLMATTA_ERROR == ret)
{
*argument = &(inst->buffer[inst->optionParser.offset]);
*argLen = inst->optionParser.len;
ret = SHELLMATTA_OK;
}
else
{
switch(argtype)
{
case SHELLMATTA_OPT_ARG_REQUIRED:
ret = findNextHunk(inst);
if(SHELLMATTA_OK == ret)
{
*argument = &(inst->buffer[inst->optionParser.offset]);
*argLen = inst->optionParser.len;
}
break;
case SHELLMATTA_OPT_ARG_OPTIONAL:
/*! -# treat anything not starting with '-' as argument */
if('-' != peekNextHunk(inst))
{
ret = findNextHunk(inst);
if(SHELLMATTA_OK == ret)
{
*argument = &(inst->buffer[inst->optionParser.offset]);
*argLen = inst->optionParser.len;
}
}
break;
default:
/* nothing to do */
break;
}
}
}
} }
(void)argument; (void)argument;
@ -88,12 +281,13 @@ shellmatta_retCode_t shellmatta_opt_long( shellmatta_handle_t handle,
/** /**
* @brief initializes the option parser instance * @brief initializes the option parser instance
* @param[in, out] inst pointer to a shellmatta instance * @param[in, out] inst pointer to a shellmatta instance
* @param[in] argStart start offset of the arguments (after command name/alias)
*/ */
shellmatta_retCode_t shellmatta_opt_init(shellmatta_instance_t *inst) shellmatta_retCode_t shellmatta_opt_init(shellmatta_instance_t *inst, uint32_t argStart)
{ {
/*! -# initialize all relevant option parser variables */ /*! -# initialize all relevant option parser variables */
inst->optionParser.offset = 0u; inst->optionParser.nextOffset = argStart;
return SHELLMATTA_OK; return SHELLMATTA_OK;
} }

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@ -34,7 +34,8 @@ shellmatta_retCode_t shellmatta_opt_long( shellmatta_handle_t handle,
char **argument, char **argument,
uint32_t *argLen); uint32_t *argLen);
shellmatta_retCode_t shellmatta_opt_init( shellmatta_instance_t *inst); shellmatta_retCode_t shellmatta_opt_init( shellmatta_instance_t *inst,
uint32_t argStart);
#endif #endif

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@ -21,7 +21,52 @@ extern "C" {
static uint32_t write_callCnt = 0u; static uint32_t write_callCnt = 0u;
static char write_data[1024]; static char write_data[1024];
static uint32_t write_length; static uint32_t write_length;
static uint32_t cntA = 0u;
static uint32_t cntB = 0u;
static uint32_t cntC = 0u;
static uint32_t cntD = 0u;
static uint32_t cntE = 0u;
static uint32_t cntF = 0u;
static uint32_t cntDef = 0u;
static char *argA = NULL;
static char *argB = NULL;
static char *argC = NULL;
static char *argD = NULL;
static char *argE = NULL;
static char *argF = NULL;
static char *argDef = NULL;
static uint32_t lenA = 0u;
static uint32_t lenB = 0u;
static uint32_t lenC = 0u;
static uint32_t lenD = 0u;
static uint32_t lenE = 0u;
static uint32_t lenF = 0u;
static uint32_t lenDef = 0u;
static void initTestcase(void)
{
cntA = 0u;
cntB = 0u;
cntC = 0u;
cntD = 0u;
cntE = 0u;
cntF = 0u;
cntDef = 0u;
argA = NULL;
argB = NULL;
argC = NULL;
argD = NULL;
argE = NULL;
argF = NULL;
argDef = NULL;
lenA = 0u;
lenB = 0u;
lenC = 0u;
lenD = 0u;
lenE = 0u;
lenF = 0u;
lenDef = 0u;
}
static shellmatta_retCode_t writeFct(const char* data, uint32_t length) static shellmatta_retCode_t writeFct(const char* data, uint32_t length)
{ {
@ -44,28 +89,53 @@ static shellmatta_retCode_t parseOpts(shellmatta_handle_t handle, const char *ar
char option; char option;
char *argumentString; char *argumentString;
uint32_t argumentLength; uint32_t argumentLength;
uint32_t optionCount = 0u;
while(SHELLMATTA_OK == shellmatta_opt(handle, (char*)"abcde:f::", &option, &argumentString, &argumentLength)) while(SHELLMATTA_OK == shellmatta_opt(handle, (char*)"abcde:f::", &option, &argumentString, &argumentLength))
{ {
optionCount ++;
switch(option) switch(option)
{ {
case 'a': case 'a':
cntA ++;
argA = argumentString;
lenA = argumentLength;
break; break;
case 'b': case 'b':
cntB ++;
argB = argumentString;
lenB = argumentLength;
break; break;
case 'c': case 'c':
cntC ++;
argC = argumentString;
lenC = argumentLength;
break; break;
case 'd': case 'd':
cntD ++;
argD = argumentString;
lenD = argumentLength;
break; break;
case 'e': case 'e':
cntE ++;
argE = argumentString;
lenE = argumentLength;
break; break;
case 'f': case 'f':
cntF ++;
argF = argumentString;
lenF = argumentLength;
break; break;
default: default:
cntDef ++;
argDef = argumentString;
lenDef = argumentLength;
break; break;
} }
} }
shellmatta_printf(handle, "parseOpts - cnt: %u\r\n", optionCount);
return SHELLMATTA_OK; return SHELLMATTA_OK;
} }
shellmatta_cmd_t parseOptsCmd = {(char*)"parseOpts", (char*)"opt", NULL, NULL, parseOpts, NULL}; shellmatta_cmd_t parseOptsCmd = {(char*)"parseOpts", (char*)"opt", NULL, NULL, parseOpts, NULL};
@ -83,7 +153,7 @@ TEST_CASE( "shellmatta option parser 1" ) {
shellmatta_handle_t handle; shellmatta_handle_t handle;
char buffer[1024]; char buffer[1024];
char historyBuffer[1024]; char historyBuffer[1024];
//char *dummyData = (char*)"\r\nshellmatta->"; char *dummyData = (char*)"parseOpts -a -e meow\r\nparseOpts - cnt: 2\r\n\r\nshellmatta->";
shellmatta_doInit( &inst, shellmatta_doInit( &inst,
&handle, &handle,
@ -95,13 +165,22 @@ TEST_CASE( "shellmatta option parser 1" ) {
NULL, NULL,
writeFct); writeFct);
initTestcase();
write_callCnt = 0u; write_callCnt = 0u;
memset(write_data, 0, sizeof(write_data)); memset(write_data, 0, sizeof(write_data));
write_length = 0u; write_length = 0u;
shellmatta_processData(handle, (char*)"parseOpts -a -e meow\r", 1); shellmatta_addCmd(handle, &parseOptsCmd);
// CHECK( write_length == 14u); shellmatta_processData(handle, (char*)"parseOpts -a -e meow\r", 21);
// REQUIRE( strcmp(dummyData, write_data) == 0);
REQUIRE( 1 == 1 ); CHECK( cntA == 1u );
CHECK( NULL == argA);
CHECK( 0u == lenA );
CHECK( cntE == 1u );
CHECK(((NULL != argE) && (0u == memcmp(argE, "meow", 4))));
CHECK( lenE == 4u );
CHECK( (cntB == 0u && cntC == 0u && cntD == 0u && cntF == 0u && cntDef == 0u) );
CHECK( write_length == 56u);
REQUIRE( strcmp(dummyData, write_data) == 0);
} }

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@ -0,0 +1,162 @@
#include "test/framework/catch.hpp"
#include "src/shellmatta_opt.c"
#include <string.h>
TEST_CASE( "shellmatta_opt findNextHunk easy" ) {
shellmatta_retCode_t ret = SHELLMATTA_OK;
shellmatta_instance_t inst;
char *dummyData = (char*) "This is Sparta";
char buffer[1024u];
memcpy(buffer, dummyData, strlen(dummyData));
inst.buffer = buffer;
inst.bufferSize = sizeof(buffer);
inst.inputCount = 14;
inst.optionParser.nextOffset = 4u;
ret = findNextHunk(&inst);
CHECK( ret == SHELLMATTA_OK );
CHECK( inst.optionParser.offset == 5u);
CHECK( inst.optionParser.len == 2u);
ret = findNextHunk(&inst);
CHECK( ret == SHELLMATTA_OK );
CHECK( inst.optionParser.offset == 8u);
CHECK( inst.optionParser.len == 6u);
ret = findNextHunk(&inst);
REQUIRE( ret == SHELLMATTA_ERROR );
}
TEST_CASE( "shellmatta_opt findNextHunk quotation 1" ) {
shellmatta_retCode_t ret = SHELLMATTA_OK;
shellmatta_instance_t inst;
char *dummyData = (char*) "This is Sparta \"argument with spaces\"";
char buffer[1024u];
memcpy(buffer, dummyData, strlen(dummyData));
inst.buffer = buffer;
inst.bufferSize = sizeof(buffer);
inst.inputCount = strlen(dummyData);
inst.optionParser.nextOffset = 4u;
ret = findNextHunk(&inst);
CHECK( ret == SHELLMATTA_OK );
CHECK( inst.optionParser.offset == 5u);
CHECK( inst.optionParser.len == 2u);
ret = findNextHunk(&inst);
CHECK( ret == SHELLMATTA_OK );
CHECK( inst.optionParser.offset == 8u);
CHECK( inst.optionParser.len == 6u);
ret = findNextHunk(&inst);
CHECK( ret == SHELLMATTA_OK );
CHECK( inst.optionParser.offset == 15u);
CHECK( inst.optionParser.len == 20u);
CHECK( 0 == memcmp(&(inst.buffer[inst.optionParser.offset]), "argument with spaces", 20));
ret = findNextHunk(&inst);
REQUIRE( ret == SHELLMATTA_ERROR );
}
TEST_CASE( "shellmatta_opt findNextHunk quotation 2" ) {
shellmatta_retCode_t ret = SHELLMATTA_OK;
shellmatta_instance_t inst;
char *dummyData = (char*) "This is Sparta 'argument with spaces'";
char buffer[1024u];
memcpy(buffer, dummyData, strlen(dummyData));
inst.buffer = buffer;
inst.bufferSize = sizeof(buffer);
inst.inputCount = strlen(dummyData);
inst.optionParser.nextOffset = 4u;
ret = findNextHunk(&inst);
CHECK( ret == SHELLMATTA_OK );
CHECK( inst.optionParser.offset == 5u);
CHECK( inst.optionParser.len == 2u);
ret = findNextHunk(&inst);
CHECK( ret == SHELLMATTA_OK );
CHECK( inst.optionParser.offset == 8u);
CHECK( inst.optionParser.len == 6u);
ret = findNextHunk(&inst);
CHECK( ret == SHELLMATTA_OK );
CHECK( inst.optionParser.offset == 15u);
CHECK( inst.optionParser.len == 20u);
CHECK( 0 == memcmp(&(inst.buffer[inst.optionParser.offset]), "argument with spaces", 20));
ret = findNextHunk(&inst);
REQUIRE( ret == SHELLMATTA_ERROR );
}
TEST_CASE( "shellmatta_opt findNextHunk quotation escaped" ) {
shellmatta_retCode_t ret = SHELLMATTA_OK;
shellmatta_instance_t inst;
char *dummyData = (char*) "This is Sparta \"argument with \\\"spaces\"";
char buffer[1024u];
memcpy(buffer, dummyData, strlen(dummyData));
inst.buffer = buffer;
inst.bufferSize = sizeof(buffer);
inst.inputCount = strlen(dummyData);
inst.optionParser.nextOffset = 4u;
ret = findNextHunk(&inst);
CHECK( ret == SHELLMATTA_OK );
CHECK( inst.optionParser.offset == 5u);
CHECK( inst.optionParser.len == 2u);
ret = findNextHunk(&inst);
CHECK( ret == SHELLMATTA_OK );
CHECK( inst.optionParser.offset == 8u);
CHECK( inst.optionParser.len == 6u);
ret = findNextHunk(&inst);
CHECK( ret == SHELLMATTA_OK );
CHECK( inst.optionParser.offset == 15u);
CHECK( inst.optionParser.len == 21u);
CHECK( 0 == memcmp(&(inst.buffer[inst.optionParser.offset]), "argument with \"spaces", 21));
ret = findNextHunk(&inst);
REQUIRE( ret == SHELLMATTA_ERROR );
}
TEST_CASE( "shellmatta_opt findNextHunk quotation missing closing quotation" ) {
shellmatta_retCode_t ret = SHELLMATTA_OK;
shellmatta_instance_t inst;
char *dummyData = (char*) "This is Sparta \"argument with \\\"spaces";
char buffer[1024u];
memcpy(buffer, dummyData, strlen(dummyData));
inst.buffer = buffer;
inst.bufferSize = sizeof(buffer);
inst.inputCount = strlen(dummyData);
inst.optionParser.nextOffset = 4u;
ret = findNextHunk(&inst);
CHECK( ret == SHELLMATTA_OK );
CHECK( inst.optionParser.offset == 5u);
CHECK( inst.optionParser.len == 2u);
ret = findNextHunk(&inst);
CHECK( ret == SHELLMATTA_OK );
CHECK( inst.optionParser.offset == 8u);
CHECK( inst.optionParser.len == 6u);
ret = findNextHunk(&inst);
REQUIRE( ret == SHELLMATTA_ERROR );
}

View File

@ -19,6 +19,7 @@ TEST_CASE( "shellmatta_insertChars normal call" ) {
shellmatta_instance_t inst; shellmatta_instance_t inst;
char buffer[20] = "abcdefghij\0\0\0\0\0\0\0\0\0"; char buffer[20] = "abcdefghij\0\0\0\0\0\0\0\0\0";
memset(&inst, 0, sizeof(inst));
inst.buffer = buffer; inst.buffer = buffer;
inst.bufferSize = 20; inst.bufferSize = 20;
inst.cursor = 8; inst.cursor = 8;
@ -45,6 +46,7 @@ TEST_CASE( "shellmatta_insertChars overwrite" ) {
shellmatta_instance_t inst; shellmatta_instance_t inst;
char buffer[20] = "abcdefghij\0\0\0\0\0\0\0\0\0"; char buffer[20] = "abcdefghij\0\0\0\0\0\0\0\0\0";
memset(&inst, 0, sizeof(inst));
inst.buffer = buffer; inst.buffer = buffer;
inst.bufferSize = 20; inst.bufferSize = 20;
inst.cursor = 8; inst.cursor = 8;
@ -72,6 +74,7 @@ TEST_CASE( "shellmatta_insertChars append" ) {
shellmatta_instance_t inst; shellmatta_instance_t inst;
char buffer[20] = "abcdefghij\0\0\0\0\0\0\0\0\0"; char buffer[20] = "abcdefghij\0\0\0\0\0\0\0\0\0";
memset(&inst, 0, sizeof(inst));
inst.buffer = buffer; inst.buffer = buffer;
inst.bufferSize = 20; inst.bufferSize = 20;
inst.cursor = 10; inst.cursor = 10;
@ -99,6 +102,7 @@ TEST_CASE( "shellmatta_insertChars 0 length" ) {
shellmatta_instance_t inst; shellmatta_instance_t inst;
char buffer[20] = "abcdefghij\0\0\0\0\0\0\0\0\0"; char buffer[20] = "abcdefghij\0\0\0\0\0\0\0\0\0";
memset(&inst, 0, sizeof(inst));
inst.buffer = buffer; inst.buffer = buffer;
inst.bufferSize = 20; inst.bufferSize = 20;
inst.cursor = 8; inst.cursor = 8;