main.c

#include "headerFile.h"

int main(void) {
    char input[MAX_LEN+1];
    char original_path[1024]; strcpy (original_path, getenv("PATH"));
    char *tknCmd;
    char *tknArg[50];

    int history_count = 0;
    char history[20][MAX_LEN+1];
    char historyPath[] = ".hist_list";

    // Get the path to the user's home directory - goes at start
    char* home = getenv("HOME");
    if (home == NULL) {
        fprintf(stderr, "Unable to get home directory\n");
        exit(EXIT_FAILURE);
    }

    // Changes the current working directory to the user's home directory - goes at start
    if (chdir(home) != 0) {
        fprintf(stderr, "Unable to change directory to %s\n", home);
        exit(EXIT_FAILURE);
    }

    Alias aliases[10];
    int numAliases=0;

    readAliasesFromFile(".aliases.txt",aliases,&numAliases);

    // read in from savedHistory.txt and update the counter to contain the latest from the history
    FILE *readFile = fopen(historyPath,"r");
    if (!readFile){
        printf("Error! Could not open file, so we made you one \n");
    }
    else{
        char line[20][MAX_LEN];
        while(fgets(line[history_count], MAX_LEN, readFile)){
            line[history_count][strcspn(line[history_count], "\n")] = '\0';
            strcpy(history[history_count], line[history_count]);
            history_count++;
        }
        fclose(readFile);
    }

    // Checks for "exit" and EOF (generated by Ctrl-D)
    while (!feof(stdin)) {

        for (int u = 0; u < 49; u++) {
            tknArg[u] = NULL;
        }

        //Take input from user
        printf(">~>~> ");
        fgets(input, MAX_LEN, stdin);

        if(DEBUG){ printf("%s", input); printf("\n"); }

        //Takes user input again if it is null or over 512 chars
        while(checkInputLength(input)==1 || is_null_string(input)==1){
            flushInput(input);
            printf(">~>~> ");
            fgets(input, MAX_LEN, stdin);
        }

        //Remove newline character at the end of the string
        input[strcspn(input, "\n")] = '\0';

        // functions here that replace input with command saved in history if !! / !<no.> / !-<no.>
        if (input[0] == '!') {
            // for commands that start with !-
            if (input[1] == '-') {
                if (strlen(input) > 4){
                    printf("error in calling history command, please use correct formatting\n");
                    continue;
                }
                int position = atoi(input + 2);
                if (position < history_count + 1 && position > 0) {
                    printf("%s \n",history[history_count - position]);
                    strcpy(input, history[history_count - position]);
                }
                else {
                    printf("theres nothing in that history you muffin \n");
                    continue;
                }
            }
            else if (input[1] == '!') {
                if (strlen(input) > 2 ){
                    printf("error in calling history command, please use correct formatting\n");
                    continue;
                }
                if (history_count > 0) {
                    printf("%s \n",history[history_count-1]);
                    strcpy(input, history[history_count-1]);
                }
                else{
                    printf("theres nothing in that history you muffin \n");
                    continue;
                }
            }
            else{
                if (strlen(input) > 3 ){
                    printf("error in calling history command, please use correct formatting\n");
                    continue;
                }
                int position = atoi (input + 1);
                if (position < history_count + 1 && position > 0) {
                    printf("%s \n",history[position-1]);
                    strcpy(input, history[position - 1]);
                }
                else {
                    printf("theres nothing in that history you muffin \n");
                    continue;
                }
            }
        }

        // saves the input to history after it's been validated
        else if (strlen(input) != 0){
            if (history_count == MAX_HISTORY_SIZE) {
                // Shift history array to make room for new command
                for (int i = 0; i < MAX_HISTORY_SIZE - 1; i++) {
                    strcpy(history[i], history[i+1]);
                }
                strcpy(history[MAX_HISTORY_SIZE-1], input);
            } else {
                strcpy(history[history_count++], input);
            }
        }


        // Checks for " " in the input line and creates a token
        char *token = strtok(input, DELIMITERS);
        //Check if token is exit command
        if(token!=NULL){
            if(checkExit(token)){
                break;
            }
        }

        //Splits the input tokens into tknArgs and tknCmd
        int i = 0;
        while (token != NULL) {
            tknArg[i] = token;
            i++;
            token = strtok(NULL, DELIMITERS);
        }
        tknArg[i] = NULL;
        tknCmd = tknArg[0];

        // Alias parameter handling
        if(tknCmd!=NULL){
            if(strcmp(tknCmd,"alias")==0) {
                if (tknArg[1] == NULL) {
                    printAliases(aliases, numAliases);
                } else {
                    if(tknArg[2]==NULL){
                        printf("Error alias must contain parameters\n");
                    }
                    else if(numAliases==10&&(posInAlias(aliases,tknArg[1]))==-1){
                        printf("Error aliases are full, remove an alias if you want to map a new one!\n");
                    } else {
                        addAlias(aliases, &numAliases, tknArg[1],  &tknArg[2], i - 2);
                    }
                }
                continue;
            }
            if(strcmp(tknCmd,"unalias")==0){
                if(tknArg[1]==NULL){
                    printf("Error unalias must contain parameters\n");
                }
                else{
                unAlias(tknArg[1],aliases,&numAliases);}
                continue;
            }
        }
        int numOut=0;
        if(tknCmd!=NULL){
            //substitute for aliases
            char** substituted = substituteAlias(aliases,numAliases,tknArg,i,&numOut);

            //converts char** to char* []
            convertCharArr(substituted, countItemsOfArray(substituted), (char **) &tknArg);
            free(substituted);
        }
        tknCmd = tknArg[0];
        i = countItemsOfArray(tknArg);
        tknArg[i]=NULL;

        tknArg[numOut]=NULL;

        if(tknCmd!=NULL){
            if(checkExit(tknCmd)){
                break;
            }
        }


        if (tknCmd != NULL){
            if (strcmp(tknCmd, "getpath") == 0) {
                if (tknArg[1] == NULL){
                    printf("%s", getpath());
                    printf("\n");
                }
                else{
                    printf("Error! command has extra parameters when not needed \n");
                }
            }
            else if (strcmp(tknCmd, "setpath") == 0) {
                if (tknArg[1] == NULL) {
                    printf("Error! command has no parameters it needs path \n");
                }
                else if (tknArg[2] != NULL) {
                    printf("Error! command has extra parameters, just use one path \n");
                }
                else {
                    setpath(tknArg[1]);
                }
            }
            else if (strcmp(tknCmd, "cd") == 0) {
                if(tknArg[1] == NULL) {
                    cd();
                }
                else if (tknArg[2]  == NULL){
                        cdArg(tknArg[1]);
                }
                else {
                    printf("too many parameters to cd, %s not needed\n", tknArg[2]);
                }
            }
            else if (strcmp(tknArg[0], "history") == 0){
                if (tknArg[1] == NULL){
                    printHistory(history, history_count);
                }
                else {
                    printf("cannot print history, %s not needed\n", tknArg[1]);
                }
            }
            else {
                processFork(tknCmd,tknArg);
            }
        }
    }
    writeHistoryToFile(historyPath, history_count, history);
    writeAliasToFile(aliases, numAliases);
    restorePath(original_path);
    exit(0);
}