Функция void delete". Требуется идентификатор - C (СИ)

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#define MAX_STRING_LENGTH 256
 
FILE *db = NULL;
char *dbdir = NULL;
 
typedef struct {
    unsigned int id;
    unsigned int deleted;
    char name[MAX_STRING_LENGTH];
    float cost;
    char supplier[MAX_STRING_LENGTH];
    
} merch;
 
void
printMenu(){
    printf("1. Add merch\n");
    printf("2. Delete merch\n");
    printf("3. Restore\n");
    printf("4. Save as\n");
    printf("5. View merch of supplier\n");
    printf("6. View merch with cost lesser than setting\n");
    printf("7. View all\n");
    printf("0. Exit\n");
    printf("\n");
}
 
void 
loadcfg(char *name){
    char *cfgname = (char *) malloc (strlen(name) + 1);
    memset(cfgname, 0, strlen(name) + 1);
    
    strcpy (cfgname, name);
    
    int haveDot = 0;
    int i = strlen(name) - 1;
    while ( i >= 0 && name[i] != '/'){
        if (name[i] == '.'){
            haveDot = i;
            break;
        }
        i--;
    }
    
    if (haveDot){
        if (strlen(name) - 1 - haveDot < 3)
            cfgname = (char *) realloc (cfgname, 5 + haveDot);
        cfgname[haveDot + 1] = 'c';
        cfgname[haveDot + 2] = 'f';
        cfgname[haveDot + 3] = 'g';
        cfgname[haveDot + 4] = '\0';
    }
    else{
        cfgname = (char *) realloc (cfgname, strlen(name) + 5);
        cfgname[strlen(name)] = '.';
        cfgname[strlen(name) + 1] = 'c';
        cfgname[strlen(name) + 2] = 'f';
        cfgname[strlen(name) + 3] = 'g';
        cfgname[strlen(name) + 4] = '\0';
    }
    
    FILE *cfg = fopen(cfgname, "r+b");
    if (cfg == NULL){
        printf("Cfg file %s not found\n", cfgname);
        exit(1);
    }
    
    char *cfgline = (char *) malloc (MAX_STRING_LENGTH);
    memset(cfgline, 0, MAX_STRING_LENGTH);
    fgets(cfgline, MAX_STRING_LENGTH, cfg);
    printf("%s\n", cfgline);
    
    char *tmp = 0;
    if (strstr(cfgline, "DB = ")[0] == cfgline[0]){
        
        dbdir = (char *) malloc (MAX_STRING_LENGTH);
        memset(dbdir, 0, MAX_STRING_LENGTH);
        int i = 5;
        while (cfgline[i] != '\0'){
            dbdir[i - 5] = cfgline[i];
            i++;
        }
        dbdir[i] = '\0';
    }
    else{
        printf("Cfg file have errors\n");
        exit(0);
    }
    
}
void 
addMerch(){
    merch *pnew = (merch *) malloc (sizeof(merch));
    memset(pnew, 0, sizeof(merch));
    pnew->id = 1;
    printf("Input merch name: ");
    scanf("%s", &pnew->name);
    printf("Input supplier name: ");
    scanf("%s", &pnew->supplier);
    printf("Input merch cost: ");
    scanf("%f", &pnew->cost);
    merch *tmp = (merch *) malloc (sizeof(merch));
    memset(tmp, 0, sizeof(merch));
    fseek(db, 0, SEEK_SET);
    while (!feof(db)){
        fread(tmp, sizeof(merch), 1, db);
        if (tmp->deleted != 0){
            pnew->id = tmp->id;
            fseek(db, sizeof(merch) * -1, SEEK_CUR);
            break;
        }
    }
    if (pnew->id == 1)
        pnew->id = tmp->id + 1;
    fwrite(pnew, sizeof(merch), 1, db);
    free(tmp);
    free(pnew);
}
 
void view(merch *m){
    printf("ID: %d\n", m->id);
    printf("Name: %s\n", m->name);
    printf("Cost: %f\n", m->cost);
    printf("Supplier's name: %s\n", m->supplier);
}
 
int 
viewAll(){
    int isEmpty = 1;
    fseek(db, 0, SEEK_SET);
    merch *tmp = (merch *) malloc (sizeof(merch));
    while (!feof(db)){
        memset(tmp, 0, sizeof(merch));
        if (fread(tmp, sizeof(merch), 1, db) > 0)
            if (tmp->deleted == 0){
                isEmpty = 0;
                view(tmp);
            }
        printf("\n");
    }
    free(tmp);
    return isEmpty;
}
 
int 
viewDeleted(){
    int haveDeleted = 0;
    fseek(db, 0, SEEK_SET);
    merch *tmp = (merch *) malloc (sizeof(merch));
    printf("\nList of deleted ... :\n");
    while (!feof(db)){
        memset(tmp, 0, sizeof(merch));
        if (fread(tmp, sizeof(merch), 1, db) > 0){
            if (tmp->deleted != 0){
                haveDeleted = 1;
                view(tmp);
            }
        }
        printf("\n");
    }
    free(tmp);
    return haveDeleted;
}
 
void
restore(unsigned int id){
    fseek(db, 0, SEEK_SET);
    merch *tmp = (merch *) malloc (sizeof(merch));
    while (!feof(db)){
        memset(tmp, 0, sizeof(merch));
        fread(tmp, sizeof(merch), 1, db);
        if (tmp->id == id && tmp->deleted != 0){
            tmp->deleted = 0;
            fseek(db, sizeof(merch) * -1, SEEK_CUR);
            fwrite(tmp, sizeof(merch), 1, db);
            break;
        }
    }
    free(tmp);
}
 
void delete(unsigned int id){
    fseek(db, 0, SEEK_SET);
    merch *tmp = (merch *) malloc (sizeof(merch));
    while (!feof(db)){
        memset(tmp, 0, sizeof(merch));
        fread(tmp, sizeof(merch), 1, db);
        if (tmp->id == id && tmp->deleted == 0){
            tmp->deleted = 1;
            fseek(db, sizeof(merch) * -1, SEEK_CUR);
            fwrite(tmp, sizeof(merch), 1, db);
            break;
        }
    }
    free(tmp);
}
 
void
saveAs(){
    printf("Input filename: ");
    char *pfilename = (char *) malloc (MAX_STRING_LENGTH);
    memset(pfilename, 0, MAX_STRING_LENGTH);
    scanf("%s", pfilename);
    
    FILE *ndb =  fopen(pfilename, "w+b");
    fseek(db, 0, SEEK_SET);
    
    merch *tmp = (merch *) malloc (sizeof(merch));
        
    while (!feof(db)){
        memset(tmp, 0, sizeof(merch));
        fread(tmp, sizeof(merch), 1, db); 
        fwrite(tmp, sizeof(merch), 1, ndb);
    }
    free(pfilename);
    fclose(ndb);
}
 
int 
main(int argc, char **argv){
    loadcfg(argv[0]);
    db = fopen(dbdir, "r+b");
    if (db == NULL)
        db = fopen(dbdir, "w+b");
    if (db == NULL)
        return -1;
    fseek(db, 0, SEEK_END);
    while (1){
        printMenu();
        printf(">> ");
        int opt = 0;
        scanf("%d", &opt);
        switch (opt){
        case 0:
            fclose(db);
            return 0;
        case 1:
            addMerch();
            break;
        case 2:
        if (!viewAll()){
            unsigned int id = 0;
            printf ("Input detele id: ");
            scanf("%d", &id);
            delete(id);
            break;
        }
        case 3:
            if (viewDeleted()){
                unsigned int id = 0;
                printf ("Input restore id: ");
                scanf("%d", &id);
                restore(id);
            }
            break;
        case 4:
            saveAs();
            break;
        case 5:
            printf("Input supplier name: ");
            char *msupplier = (char *) malloc (MAX_STRING_LENGTH);
            memset(msupplier, 0, MAX_STRING_LENGTH);
            scanf("%s", msupplier);
            fseek(db, 0, SEEK_SET);
            merch *tmp = (merch *) malloc (sizeof(merch));
            while (!feof(db)){
                memset(tmp, 0, sizeof(merch));
                if (fread(tmp, sizeof(merch), 1, db) > 0)
                    if (!strcmp(tmp->supplier, msupplier)){
                        view(tmp);
                        printf("\n");
                    }
            }
            free(msupplier);
            free(tmp);
            break;
        case 6:
            printf("Input cost: ");
            float mcost = 0;
            scanf("%f", &mcost);
            fseek(db, 0, SEEK_SET);
            tmp = (merch *) malloc (sizeof(merch));
            while (!feof(db)){
                memset(tmp, 0, sizeof(merch));
                if (fread(tmp, sizeof(merch), 1, db) > 0)
                    if (tmp->cost < mcost)
                        view(tmp);
                printf("\n");
            }
            free(tmp);
            break;
                
        case 7:
            viewAll();
            break;
        default:
            printf("Unknow\n");
        }
    }
    return 0;
}