//Checks to see when a variable is used
nshUse(char* value){
EnvP temp;
//Check for @ to indicate variable usage
if(value[0] == '@')
{
//Find position of @ character
char* pos = strchr(value,'@');
//Check to see if @ is in complex string
if (nshComplex(value,'@') == 1)
return;
//Make sure variable exists
if (nshFind(var,(pos+1)) != NULL)
{
//Find variable that matches
temp = nshFind(var,(pos+1));
//value becomes the used variable value
strcpy(value,temp->value);
}
//Check to see if value exists but is being extended (ex. value = @one!@two where one and two exist)
nshExtend(value);
}
}
//handles all user input
userInput(){
//Clear input fields
command = NULL;
memset(&input,'\0',sizeof(input));
memset(&first,'\0',sizeof(first));
memset(&second,'\0',sizeof(second));
memset(&third,'\0',sizeof(third));
//Take input from user
printf("nsh3_WesJos$ ");
fgets(input,80,stdin);
commentfilter(input);//removes the text after a comment but not inside a complex string from a command.
//Split the input the user provides
splitInput(input);
//Make sure command or alias exists
if ((nshFind(alias,first) == NULL) && (nshFind(native,first) == NULL))
{
printf("\tCommand not found.\n");
userInput();
}
else
{
//Checks if alias or native command passed fail test
if (nshFind(alias,first) == NULL)
command = nshFind(native,first);
else
{
command = nshFind(alias,first);
handleAlias(command->value);
}
//Check command
if ((strcmp(command->value,"set")==0) || (strcmp(first,"set") == 0))
commandSet(&var,second,third);
if ((strcmp(command->value,"alias")==0) || (strcmp(first,"alias") == 0))
commandSet(&alias,second,third);
if ((strcmp(command->value,"tes") == 0) || (strcmp(first,"tes") == 0))
nshDelete(&var,second);
if ((strcmp(command->value,"saila") == 0) || (strcmp(first,"saila") == 0))
nshDelete(&alias,second);
if ((strcmp(command->value,"exit") == 0) || (strcmp(first,"exit") == 0))
cont = 0;
}
}
//Displays, inserts, or updates a new entry
commandSet(EnvP *list, char* name, char* value){
EnvP com,var,temp;
//make sure var name exists
if (nshFind(*list,name) != NULL)
com = nshFind(*list,name);
else
com = NULL;
//Check to see if variable is being extended
nshExtend(value);
//Chec to see if variable is being used
nshUse(value);
//If a name has been recieved, check to either display or set
if (name[0] != '\0')
{
//If a value has been recieved, set it
if (value[0] != '\0')
{
//If variable already exists, update it
if (com != NULL)
{
nshUpdate(&com,name,value);
return;
}
//If a variable is being used to set value, use the value of the variable
if (nshFind(*list,value) != NULL)
{
var = nshFind(*list,value);
nshInsert(list,name,var->value);
}
//If variable doesn't exist, add it
else
nshInsert(list,name,value);
return;
}
//Makes sure variable name exists and displays an appropriate message
if (com->name == NULL)
printf("\tInvalid variable or alias\n");
else
printf("\t%s = %s\n",com->name,com->value);
return;
}
//If only the command was sent, display the given list
nshDisplay(*list);
}
int main() {
// boolean values
bool needToExecuteProgram, extendVariable, extendAtBack, extendAtFront, didComplete, checkAlias;
// counters
int wordCount, loopCount, tempCount, arrayPosition_x, arrayPosition_y;
// strings
char commandInput[100],tempWord[20],userCommand[10][30], temp[50], temp2[50], temp3[50];
// commands & variables
char *command, *arg1, *arg2, *arg3, *extending;
// declare list heads
struct node *varHP;
struct node *aliasHP;
// init to null
varHP = NULL;
aliasHP = NULL;
char mem[1000];
initialize_globals(mem, 1000);
memset(mem, 0, 1000); //all values need to be initialized to 0.
// get command input
needToExecuteProgram = TRUE;
while (needToExecuteProgram)
{
// print shell prompt
wordCount = 0;
prompt;
fgets(commandInput, 100, stdin);
// For @var to display
if(commandInput[0] == '@') {
int temporary = strlen(commandInput) -2; //to ignore "@" and "\n" in input
char temporary2[temporary];
int x = 1,y = 0;; //skip the @
while(y < temporary) {
if(commandInput[x] == '\n') //break at the newline, we don't want that included
break;
temporary2[y] = commandInput[x];
x++; //temporary[2] will hold the variable name.
y++;
}
temporary2[y] = '\0';
nshFind(varHP, temporary2);
continue;
}
//end of @var display
// break up input string from user into an array of strings to interpret
tempCount = arrayPosition_x = arrayPosition_y = 0;
// loop through each character of the string entered from the command line
for (loopCount=0; loopCount<strlen(commandInput)-1; loopCount++)
{
// if a space is found
if (commandInput[loopCount] == space)
{
// end the temp word
tempWord[tempCount] = EOS;
// place it in the command array
arrayPosition_y = 0;
wordCount++;
while (TRUE)
{
if (tempWord[arrayPosition_y] == EOS)
{
userCommand[arrayPosition_x][arrayPosition_y] = EOS;
break;
}
userCommand[arrayPosition_x][arrayPosition_y] = tempWord[arrayPosition_y];
arrayPosition_y++;
}
// move to get the next word
arrayPosition_x++;
tempCount = 0;
}
// while there are no spaces
else
{
// put the characters in a temporary word until one is found
tempWord[tempCount] = commandInput[loopCount];
tempCount++;
// if there is no space, but its the end of the user's input
if (loopCount == strlen(commandInput)-2)
{
tempWord[tempCount] = EOS;
arrayPosition_y = 0;
wordCount++;
while (TRUE)
{
if (tempWord[arrayPosition_y] == EOS)
{
userCommand[arrayPosition_x][arrayPosition_y] = EOS;
break;
}
userCommand[arrayPosition_x][arrayPosition_y] = tempWord[arrayPosition_y];
arrayPosition_y++;
}
}
}
}
// Implement whatever command was given or print the errors
// if there was input
if (wordCount > 0)
{
// get the command
command = &userCommand[0][0];
// if the command is "set"
if (strcmp(command,"set") == 0 || (matchAlias(aliasHP, "set", command))==TRUE )
{
// check for the correct amount of arguments
if (wordCount-1 <= 2)
{
// display all variables
if (wordCount == 1)
{
printVarList(nshHead(varHP));
}
// display a variable's specific value
else if (wordCount == 2)
{
arg1 = &userCommand[1][0];
nshFind(nshHead(varHP),arg1);
}
// set OR reset a variable
else
{
arg1 = &userCommand[1][0];
arg2 = &userCommand[2][0];
strcpy(temp3,userCommand[2]);
extendVariable = extendAtFront = extendAtBack = FALSE;
// if wanting to extend a variable with the new value on the back
if (temp3[0] == '@')
{
extendAtBack = TRUE;
extendVariable = FALSE;
// look for the '!' ending variable character
for(loopCount=0; loopCount < strlen(temp3); loopCount++)
{
if (temp3[loopCount] == '!')
{
extendVariable = TRUE;
temp[loopCount-1] = EOS;
// get the rest of the string to use to extend variable with
loopCount++;
int i = 0;
for (loopCount; loopCount < strlen(temp3); loopCount++)
{
temp2[i] = temp3[loopCount];
i++;
if (loopCount == (strlen(temp3) -1))
{
temp2[i] = EOS;
arg2 = temp;
arg3 = temp2;
break;
}
}
}
else if (extendVariable == TRUE)
break;
else
{
if (loopCount != 0)
temp[loopCount-1] = temp3[loopCount];
}
}
}
// test to see if user wants to extend the variable on the front of it with the new value
if (extendAtBack == FALSE)
{
extendAtFront = FALSE;
for(loopCount=0; loopCount < strlen(temp3); loopCount++)
{
if (temp3[loopCount] == '@' && temp3[loopCount-1] == '!')
{
int tempSpot, j;
j = 0;
tempSpot = loopCount + 1;
for (tempSpot; tempSpot < strlen(temp3); tempSpot++)
{
temp[j] = temp3[tempSpot];
j++;
}
temp[j] = EOS;
for (tempSpot = 0; tempSpot < (loopCount-1); tempSpot++)
{
temp2[tempSpot] = temp3[tempSpot];
}
temp2[tempSpot] = EOS;
extendAtFront = TRUE;
extendVariable = TRUE;
arg2 = temp;
arg3 = temp2;
break;
}
}
}
// Set or reset a variable
if (extendVariable == FALSE)
{
// if the head is null
if (varHP == NULL){
//varHP = (node*)nshMalloc(sizeof(node));
varHP = (node*) malloc (sizeof(node));
strcpy(varHP->name,&userCommand[1][0]);
strcpy(varHP->value, arg2);
varHP->next = NULL;
}
// if need to find its place in the list
else {
nshInsert(nshHead(varHP), arg1,arg2, VARIABLE);
}
}
else if (extendAtFront == TRUE)
{
// extendVarValue (node *head, char *set_resetValue, char *getVarValue, char *extendWith, int extendingPosition)
didComplete = extendVarValue(nshHead(varHP), arg1, arg2, arg3, varValueInBack);
if (didComplete == FALSE)
printf("Couldn't extend variable, it doesn't exist\n");
}
else {
// extendVarValue (node *head, char *set_resetValue, char *getVarValue, char *extendWith, int extendingPosition)
didComplete = extendVarValue(nshHead(varHP), arg1, arg2, arg3, varValueInFront);
if (didComplete == FALSE)
printf("Couldn't extend variable, it doesn't exist\n");
}
// reset bool values
extendVariable = extendAtFront = extendAtBack = FALSE;
}
}
else
{
printf("Error - To many arguments for the \"set\" command\n");
continue;
}
}
// if the command is "tes"
else if (strcmp(command,"tes") == 0 || (matchAlias(aliasHP, "tes", command))==TRUE )
{
// if there are not to many OR to few arguments for this command
if (wordCount-1 == 1)
{
arg1 = &userCommand[1][0];
int status;
status = nshRemove(varHP,arg1);
if (status == onlyOneNode){
varHP = NULL;
}
else if (status == popHead){
varHP = (node*) nshNext(varHP);
}
}
else
{
printf("Error - To many or to few arguments for the \"tes\" command\n");
}
}
// if the command is "alias"
else if (strcmp(command,"alias") == 0 || (matchAlias(aliasHP, "alias", command))==TRUE )
{
// if wordCount is 1 - display all aliases (External & Internal)
if (wordCount == 1)
{
printVarList(nshHead(aliasHP));
}
// wordCount = 2 - display a specific command alias
else if (wordCount == 2)
{
arg1 = &userCommand[1][0];
nshFind(nshHead(aliasHP),arg1);
}
// wordCout =3 - set/reset a command alias
else
{
// if the new alias is an internal command
arg1 = &userCommand[1][0];
arg2 = &userCommand[2][0];
// if the head is null
if (aliasHP == NULL){
//aliasHP = (node*)nshMalloc(sizeof(node));
aliasHP = (node*) malloc(sizeof(node));
strcpy(aliasHP->name,&userCommand[1][0]);
strcpy(aliasHP->value, arg2);
aliasHP->next = NULL;
}
// if need to find its place in the list
else {
nshInsert(nshHead(aliasHP), arg1,arg2, ALIAS);
}
}
}
// if the command is "saila"
else if (strcmp(command,"saila") == 0 || (matchAlias(aliasHP, "saila", command))==TRUE )
{
if (wordCount == 2)
{
arg1 = &userCommand[1][0];
int status;
status = nshRemove(nshHead(aliasHP),arg1);
if (status == onlyOneNode){
aliasHP = NULL;
}
else if (status == popHead){
aliasHP = (node*) nshNext(aliasHP);
}
}
else {
printf("To many arguments for 'saila' command\n");
}
}
// if the command is "exit"
else if (strcmp(command,"exit") == 0 || (matchAlias(aliasHP, "exit", command))==TRUE )
{
needToExecuteProgram = FALSE;
continue;
}
// if the command is not supported or found
else
{
printf("-bash: %s: external command not supported\n",command);
}
}
}
return END_PROGRAM;
}
