C code review shows Hasb Table features

This C code shows Hasb Table features. And code is helpful while user is in between data structure manipulation task.

code:

//Tested OK on Code::Blocks IDE 17.12.
//for Cygwin + GCC change getch() into getchar().
//Proram shows Hasb Table features.

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

typedef struct _node
{
    char *name;
    char *desc;
    struct _node *next;
} node;

#define HASHSIZE 101
static node* hashtab[HASHSIZE];

void inithashtab()
{
    int i;
    for(i=0; i<HASHSIZE; i++)
        hashtab[i]=NULL;
}

unsigned int hash(char *s)
{
    unsigned int h=0;
    for(; *s; s++)
        h=*s+h*31;
    return h%HASHSIZE;
}

node* lookup(char *n)
{
    unsigned int hi=hash(n);
    node* np=hashtab[hi];
    for(; np!=NULL; np=np->next)
    {
        if(!strcmp(np->name,n))
            return np;
    }

    return NULL;
}

char* m_strdup(char *o)
{
    int l=strlen(o)+1;
    char *ns=(char*)malloc(l*sizeof(char));
    strcpy(ns,o);
    if(ns==NULL)
        return NULL;
    else
        return ns;
}

char* get(char* name)
{
    node* n=lookup(name);
    if(n==NULL)
        return NULL;
    else
        return n->desc;
}

int install(char* name,char* desc)
{
    unsigned int hi;
    node* np;
    if((np=lookup(name))==NULL)
    {
        hi=hash(name);
        np=(node*)malloc(sizeof(node));
        if(np==NULL)
            return 0;
        np->name=m_strdup(name);
        if(np->name==NULL)
            return 0;
        np->next=hashtab[hi];
        hashtab[hi]=np;
    }
    else
        free(np->desc);
    np->desc=m_strdup(desc);
    if(np->desc==NULL)
        return 0;

    return 1;
}

/* A pretty useless but good debugging function,
   which simply displays the hashtable in (key.value) pairs
*/
void displaytable()
{
    int i;
    node *t;
    for(i=0; i<HASHSIZE; i++)
    {
        if(hashtab[i]==NULL)
            printf("()");
        else
        {
            t=hashtab[i];
            printf("(");
            for(; t!=NULL; t=t->next)
                printf("(%s.%s) ",t->name,t->desc);
            printf(")");
        }
    }
}

void cleanup()
{
    int i;
    node *np,*t;
    for(i=0; i<HASHSIZE; i++)
    {
        if(hashtab[i]!=NULL)
        {
            np=hashtab[i];
            while(np!=NULL)
            {
                t=np->next;
                free(np->name);
                free(np->desc);
                free(np);
                np=t;
            }
        }
    }
}

int main()
{
    int i;
    char* names[]= {"name","address","phone","k101","k110"};
    char* descs[]= {"Sourav","Sinagor","26300788","Value1","Value2"};

    inithashtab();
    for(i=0; i<5; i++)
        install(names[i],descs[i]);

    printf("\nDone");
    printf("\nIf we didnt do anything wrong..\n\t" "we should see %s",get("k110"));

    printf("\nInstall new phone number to Hashtable.");
    install("phone","9433120451");

    printf("\nAgain if we go right, we have %s and %s",get("k101"),get("phone"));

    /*displaytable();*/
    cleanup();
    getch();
    return 0;
}

//end of program

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...till next post, bye-bye and take care.