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Extracting, converting, filtering, sorting, and building a CSV file in C programming assignment help

The assignment deals with implementing a program to process CSV files. The program written by our C programming assignment helpers consists of several functions that can read the CSV file, convert the fields from ASCII to a determined type, sort the CSV using some of the columns, select some of the columns for the output and generate a new CSV data structure from the result. The CSV data in the program is modeled using a C struct.

Processing CSV Files in C

/* File: hw4Sort.c Author: /// Date: April 27, 2017 Statement: "Your statement that the program is entirely your work and that you have neither developed your code together with any other person nor copied program code from any other person, nor permitted your code to be copied or otherwise used by any other person, nor have you copied, modified, or otherwise used program code that you have found in any external source, including but not limited to, online sources" */ #include #include #include #define MAX_LINE 512 // maximum line length #define SORT_BY_LOCID 0 #define SORT_BY_LAT 1 typedef struct airPdata { int seqNumber; //The process output's sequence number char *LocID; //Airport's "Short Name", ie MCO char *fieldName; //Airport Name char *city; //Associated City float longitude; //Longitude float latitude; //Latitude }airPdata; /* Struct for making a linked list */ typedef struct lListAirPdata { airPdata *data; struct lListAirPdata *next; }lListAirPdata; /* struct for making an AVL */ typedef struct AVLTree { airPdata *key; struct AVLTree *left; struct AVLTree *right; struct AVLTree *parent; int balance; }AVLTree; typedef int (*CmpFunc)(airPdata *a,airPdata *b); /* comparison function definition */ int max(int a, int b) { return a > b ? a : b; } /* safe version of malloc to detect when malloc fails */ void *safe_malloc(size_t size) { void *data; data=malloc(size); if(data==NULL) { printf("Out of memory!\n"); exit(1); } return data; } /* Print the program usage */ void print_usage(char **argv) { printf("Usage:\n\t%s\tfilename.ext sortParameter\n",argv[0]); printf("\nDescription:\n\tfilename.ext\tinput filename\n"); printf("\tsortParameter\tmust be either \"a\" for alphabetical sort\n"); printf("\t \tor \"n\" for north bound exit\n"); } /* Validates the command line arguments, if an error is found it doesn't return */ void validate_arguments(int argc,char **argv) { if(argc<2 || argc>3) { printf("hw4Sort ERRROR: Invalid number of arguments.\n"); print_usage(argv); exit(1); } else if(argc==2) { if(!strcmp(argv[1],"-h")) { print_usage(argv); exit(0); } else if(argv[1][1]=='\0') { printf("hw4Sort ERRROR: Filename missing.\n"); print_usage(argv); exit(1); } else { printf("hw4Sort ERRROR: sortParameter not found.\n"); print_usage(argv); exit(1); } } } /* validate a numeric string, it returns 1 if the string contains only digits before the endchar, endpos contains the position after the last digit. Otherwise, it returns 0, and endpos is not modified. */ int valid_number(char *str,char endchar,int *endpos) { int i=0; while(str[i]!='\0' && str[i]!=endchar) { if(str[i]<'0' || str[i]>'9') return 0; i++; } if(str[i]!=endchar) return 0; *endpos=i; return 1; } /* converts a DD-MM-SS.MASD string to a decimal degree float, if the string doesn't have the correct format it returns 0.0 */ float sexag2decimal(char *degreeString) { int n,start,end; int degrees,minutes; float ssmas; float decimal; int sign; if(degreeString==NULL) return 0.0; start=0; if(!valid_number(°reeString[start],'-',&end)) return 0.0; degreeString[start+end]=0; degrees=atoi(°reeString[start]); if(degrees>180) // valid global degrees 0-180 return 0.0; if(degrees>99) // valid US degrees 0-99 return 0.0; start+=end+1; if(!valid_number(°reeString[start],'-',&end)) return 0.0; degreeString[start+end]=0; minutes=atoi(°reeString[start]); if(minutes>59) // valid minutes 0-59 return 0.0; start+=end+1; n=start+strlen(°reeString[start]); if(degreeString[n-1]=='N' || degreeString[n-1]=='E') sign=+1; else if(degreeString[n-1]=='S' || degreeString[n-1]=='W') sign=-1; else return 0.0; degreeString[n-1]=0; n=start; if(!valid_number(°reeString[start],'.',&end)) return 0.0; start+=end+1; if(!valid_number(°reeString[start],'\0',&end)) return 0.0; ssmas=atof(°reeString[n]); if(ssmas>59.9999) // valid seconds.milliarcseconds 0-59.0-9999 return 0.0; decimal = sign*(degrees + minutes/60.0 + ssmas/3600.0); return decimal; } /* insert a new node to linked list */ void insert(airPdata *data,lListAirPdata *list) { lListAirPdata *node; node=(lListAirPdata*)safe_malloc(sizeof(lListAirPdata)); node->next=list->next; // insert at the start node->data=data; list->next=node; } /* print the contents of the list */ void print(lListAirPdata *list) { lListAirPdata *node; if(list==NULL) return; node=list->next; printf("code,name,city,lat,lon\n"); while(node) { printf("%s,",node->data->LocID); printf("%s,",node->data->fieldName); printf("%s,",node->data->city); printf("%.4f,",node->data->latitude); printf("%.4f\n",node->data->longitude); node=node->next; } } /* free the contents of the list */ void free_list(lListAirPdata *list) { lListAirPdata *node,*tmp; if(list==NULL) return; node=list->next; while(node) { tmp=node; node=node->next; free(tmp->data->LocID); free(tmp->data->fieldName); free(tmp->data->city); free(tmp->data); free(tmp); } } /* Create a new AVL tree node */ AVLTree *new_tree_node(airPdata *key,AVLTree *parent) { AVLTree *node; node=(AVLTree *)safe_malloc(sizeof(AVLTree)); node->left=NULL; node->right=NULL; node->key=key; node->parent=parent; node->balance=0; return node; } /* Calculate the AVL tree node height */ int tree_height(AVLTree *n) { if (n == NULL) return -1; return 1 + max(tree_height(n->left), tree_height(n->right)); } /* Set the AVL tree node balance */ void set_tree_balance(AVLTree *n) { n->balance = tree_height(n->right) - tree_height(n->left); } /* Rotate the AVL tree node to the left */ AVLTree *tree_rotate_l(AVLTree *a) { AVLTree *b = a->right; b->parent = a->parent; a->right = b->left; if (a->right != NULL) a->right->parent = a; b->left = a; a->parent = b; if (b->parent != NULL) { if (b->parent->right == a) b->parent->right = b; else b->parent->left = b; } set_tree_balance(a); set_tree_balance(b); return b; } /* Rotate the AVL tree node to the left */ AVLTree *tree_rotate_r(AVLTree *a) { AVLTree *b = a->left; b->parent = a->parent; a->left = b->right; if (a->left != NULL) a->left->parent = a; b->right = a; a->parent = b; if (b->parent != NULL) { if (b->parent->right == a) b->parent->right = b; else b->parent->left = b; } set_tree_balance(a); set_tree_balance(b); return b; } /* Rotate the AVL tree node to the left and then to the right */ AVLTree *tree_rotate_lr(AVLTree *n) { n->left = tree_rotate_l(n->left); return tree_rotate_r(n); } /* Rotate the AVL tree node to the right and then to the left */ AVLTree *tree_rotate_rl(AVLTree *n) { n->right = tree_rotate_r(n->right); return tree_rotate_l(n); } /* Rebalance the AVL tree node, moving the root if necessary */ void tree_rebalance(AVLTree *n,AVLTree **root) { set_tree_balance(n); if (n->balance == -2) { if (tree_height(n->left->left) >= tree_height(n->left->right)) n = tree_rotate_r(n); else n = tree_rotate_lr(n); } else if (n->balance == 2) { if (tree_height(n->right->right) >= tree_height(n->right->left)) n = tree_rotate_l(n); else n = tree_rotate_rl(n); } if (n->parent != NULL) { tree_rebalance(n->parent,root); } else { *root = n; } } /* Insert a new leaf in the the AVL tree, use the give compare function for comparing values */ int tree_insert(airPdata *key,AVLTree **root,CmpFunc compare) { AVLTree *n,*parent; int goLeft; if (*root == NULL) *root = new_tree_node(key, NULL); else { n = *root; while (1) { if (!compare(n->key,key)) return 0; parent = n; goLeft = compare(n->key,key)>0; // n->key > key; n = goLeft ? n->left : n->right; if (n == NULL) { if (goLeft) parent->left = new_tree_node(key, parent); else parent->right = new_tree_node(key, parent); tree_rebalance(parent,root); break; } } } return 1; } /* Free all allocated nodes on the tree */ void free_tree(AVLTree *tree) { if(tree==NULL) return; free_tree(tree->right); free_tree(tree->left); free(tree); } /* save the tree in the airPdata linked list */ void tree_dump(AVLTree *tree,lListAirPdata *list) { if(tree==NULL) return; tree_dump(tree->right,list); insert(tree->key,list); tree_dump(tree->left,list); } /* Sort the airport list using an AVL tree and using the given comparison function, the linked list is modified and in return, it will contain the sorted data */ void sort(lListAirPdata *airports,CmpFunc compare) { lListAirPdata *node,*tmp; AVLTree *tree=NULL; if(airports==NULL) return; node=airports->next; while(node) { tmp=node; tree_insert(node->data,&tree,compare); node=node->next; free(tmp); } airports->next=NULL; tree_dump(tree,airports); free_tree(tree); // free allocated space } /* Comparison function to compare by location ID */ int compare_by_LocID(airPdata *a,airPdata *b) { return strcmp(a->LocID,b->LocID); } void sortByLocID(lListAirPdata *airports) { sort(airports,compare_by_LocID); } /* Comparison function to compare by location latitude */ int compare_by_latitude(airPdata *a,airPdata *b) { return (int)((a->latitude-b->latitude)*10000); } void sortByLatitude(lListAirPdata *airports) { sort(airports,compare_by_latitude); } /* Determines if the given location ID is a string of 3 or 4 letters without numbers, if so it returns 1, otherwiese return 0 */ int valid_locID(char *locID) { int i,n; n=strlen(locID); if(n!=3 && n!=4) return 0; for(i=0; i='0' && locID[i]<='9') return 0; return 1; } /* load the given file and parse its contents saving the parsed content in a linked list of lListAirPdata structures */ void load_file(char *filename,lListAirPdata *list) { FILE *file; char *line; int i,start,ntoken,valid; airPdata *data; file=fopen(filename,"rt"); if(file==NULL) { printf("hw4Sort ERRROR: File \"%s\" not found.\n",filename); exit(1); } list->next=NULL; line=(char*)safe_malloc(MAX_LINE); while(!feof(file)) { fgets(line,MAX_LINE,file); i=start=ntoken=0; valid=1; while(line[i] && valid) { if(line[i]==',' || line[i]=='\n') { line[i]='\0'; switch(ntoken) { case 1: if((valid=valid_locID(&line[start]))!=0) { data=(airPdata *)safe_malloc(sizeof(airPdata)); data->LocID=(char*)safe_malloc(i-start+1); strcpy(data->LocID,&line[start]); } break; case 2: data->fieldName=(char*)safe_malloc(i-start+1); strcpy(data->fieldName,&line[start]); break; case 3: data->city=(char*)safe_malloc(i-start+1); strcpy(data->city,&line[start]); break; case 8: data->latitude=sexag2decimal(&line[start]); break; case 9: data->longitude=sexag2decimal(&line[start]); break; } start=i+1; ntoken++; } i++; } if(valid) insert(data,list); } free(line); fclose(file); } int main(int argc,char **argv) { int sort_type; lListAirPdata list; validate_arguments(argc,argv); if(argv[2][1]=='\0' && (argv[2][0]=='a' || argv[2][0]=='A')) sort_type=SORT_BY_LOCID; else if(argv[2][1]=='\0' && (argv[2][0]=='n' || argv[2][0]=='N')) sort_type=SORT_BY_LAT; else { printf("hw4Sort ERRROR: sortParameter is not valid.\n"); print_usage(argv); exit(1); } load_file(argv[1],&list); if(sort_type==SORT_BY_LOCID) sortByLocID(&list); else sortByLatitude(&list); print(&list); free_list(&list); return 0; }