void sortList(struct node *head){
struct node *sort[3];
sort[0] = head;
sort[1] = (node*) nshNext(head);
//sort[2] = (node*) nshMalloc(sizeof(struct node));
sort[2] = (node*) malloc (sizeof(struct node));
while (TRUE){
if (strcmp(sort[0]->name,sort[1]->name) > 0) {
strcpy(sort[2]->name, sort[0]->name);
strcpy(sort[2]->value, sort[0]->value);
strcpy(sort[0]->name, sort[1]->name);
strcpy(sort[0]->value, sort[1]->value);
strcpy(sort[1]->name, sort[2]->name);
strcpy(sort[1]->value, sort[2]->value);
// start again at the beginning of the list
sort[0] = head;
sort[1] = (node*) nshNext(head);
}
else{
if (sort[1]->next != NULL){
sort[0] = sort[1];
sort[1] = (node*) nshNext(sort[1]);
}
else{
break;
}
}
}
}
//Delete Function
void nshDelete(EnvP *list, char* name){
EnvP temp, prev;
temp = *list;
while(temp!=NULL)
{
if(strcmp(temp->name,name) == 0)
{
if(temp==*list)
{
*list=temp->next;
nshFree(temp);
}
else
{
prev->next=temp->next;
nshFree(temp);
}
break;
}
else
{
prev=temp;
nshNext(&temp);
}
}
}
void printVarList(struct node *head){
// create a node to track the place
struct node *place;
place = head;
if (place != NULL) {
printf("%s=%s\n",place->name,place->value);
while(place->next != NULL){
place = (node*) nshNext(place);
printf("%s=%s\n",place->name, place->value);
}
}
}
//Update function
nshUpdate(EnvP *list, char* name, char* value){
EnvP temp;
temp = *list;
while(temp!=NULL)
{
if(strcmp(temp->name,name) == 0)
{
strcpy(temp->value,value);
break;
}
else
{
nshNext(&temp);
}
}
}
// print all the nodes in list with their values
void printVarList(struct node *head){
// create a node to track the place
struct node *place;
place = head;
int x = 0;
int flag = 0;
if (place != NULL) {
while(x < strlen(place->value)) { //check if value is complex alias
if(place->value[x] == '{') {
flag = 0;
break;
}
else if(place->value[x] ==' ') { //if so, print brackets.
flag = 1;
break;
}
x++;
}
if(flag == 1) {
printf("%s {%s}\n", place->name, place->value);
}
else
printf("%s %s\n",place->name,place->value);
while(place->next != NULL){
flag = 0; //reset flag.
place = (node*) nshNext(place);
while(x < strlen(place->value)) { //check if value is complex string
if(place->value[x] == '{') {
flag = 0;
break;
}
else if(place->value[x] == ' ') { //if so, print brackets around it.
flag = 1;
break;
}
x++;
}
if(flag == 1) {
printf("%s {%s}\n", place->name, place->value);
}
else
printf("%s %s\n",place->name, place->value);
}
}
}
bool matchAlias(struct node *head, char *command, char *varName){
// create a node to track the place
struct node *place;
place = head;
if (place != NULL) {
if (strcmp(place->name,command) == 0 && strcmp(place->value,varName)==0) {
return TRUE;
}
else {
while(place != NULL){
if (strcmp(place->name,command) == 0 && strcmp(place->value,varName)==0) {
return TRUE;
}
else {
place = (node*) nshNext(place);
}
}
}
}
return FALSE;
}
//Insert function
void nshInsert(EnvP *list, char *name, char *value){
EnvP temp = (EnvP) nshMalloc(sizeof(struct env));
if (temp == NULL)
{
return;
}
EnvP left,right;
right = *list;
int found = 0;
int i;
left = NULL;
strcpy(temp->name,name);
strcpy(temp->value,value);
//Checks to see if list is empty
if (right == NULL)
{
*list=temp;
(*list)->next = NULL;
return;
}
//If list is not empty, insert new item alphabetically
while(right != NULL && found == 0)
{
for (i = 0; i < sizeof(right->name);i++)
{
//If letter matches,keep checking current var
if (right->name[i] == name[i])
{
found = 1;
continue;
}
//if new var is after current var, keep searching
else if (right->name[i] < name[i])
{
left=right;
nshNext(&right);
break;
}
//if new var is before current var
else if (right->name[i] > name[i])
{
found = 1;
break;
}
}
}
//Store new value
//Checks if new value will be first in list
if (left == NULL)
{
temp->next = *list;
*list = temp;
}
else
{
left->next = temp;
temp->next = right;
}
}
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;
}
