Read All File Contents Into A Dynamically Allocated String | C Programming Example

How to read and store all the contents of a file into a dynamically allocated string using C. An optimized solution that only requires reading the file once is created, after first creating a suboptimal but easier to understand solution that requires reading the file twice. A simple performance test is conducted to demonstrate the improved performance of the optimized solution.

[olalha]

Some of the best, most straightforward C tutorials on YouTube!

[liolio]

Thank you so much for the explanation and simple, easy to follow examples you provide. I managed to score A on my final exam only because of your videos. Immensely appreciated! Easy SUB!

[Brock-Landers]

Instant file size result even on an old XT 8088:

fseek(file, 0L, SEEK_END);
total = ftell(file);
rewind(file);

But it's nice that you gave the viewers a memory management bonus lesson. :)

[airrsongs]

I think using stat, calloc, and fread might be even more optimized.

But I like the way you take us through this tutorial. Just subscribed to the channel.
👍

[D_Ladybug]

Weldone boss. I love you.

kindly consider do an explanatory video about bit manipulations, their uses and how.. especially with number.. odd numbers, even numbers and other applications

[technicalgamer]

bro you are so underrated came to your channel and got answers for those questions which i think that was none sense and finally getting 5th

[atiyahussain]

Hi, I wanted to ask if you have a char array, where we have stored lines from a file, is there a way to check the type of the elements stored? So, for example if you iterate through the char array, that contains lines from a file, you come across a digit, convert it to a double. I'm working on a calculator project in c, that requires me to push elements of type double onto a stack and perform operations on them, once we come across a string in the file. However, I'm having difficulties converting the lines to ints and pushing them onto the stack. Is there anyway you could help? Thanks.

[funnymonkeypicture]

This video helped a lot so thank-you. However i'm trying to do this exact thing except store each line of the file into a 2D string array so each line is it's own string. Would it be better to just use the method you have shown then use strtok() with \0 as the delimiter or is there a better way to go about this? Thanks Subscribed

[yigitbulut]

How do we make a string array for each line instead of just one big string?

[ivanmartic]

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
typedef struct studenti
{
char ime[20], prezime[20];
int ocena;
double prosek;
struct studenti *sledeci;
}STUDENTI;
STUDENTI *napravi(char *ime, char *prezime, int ocena)
{
STUDENTI
strcpy(novi->ime, ime);
strcpy(novi->prezime, prezime);
novi->ocena=ocena;
novi->sledeci=NULL;
return novi;
}
STUDENTI *dodaj(STUDENTI *glava, char *ime, char *prezime, int ocena)
{

STUDENTI *novi=napravi(ime, prezime, ocena);
if (glava==NULL)
{
glava=novi;
return glava;
}

glava->sledeci=novi;
}
STUDENTI *ucitaj(STUDENTI *glava, char*fajl)
{
FILE *fp=fopen(fajl, "r");
char linija[150], ime[25], prezime[25];
int ocena;
int pr=0;
int suma=0;
while(fgets(linija, sizeof(linija), fp))
{
char *token=strtok(linija, " ");
int br=0;
while(token!=NULL)
{
if(br==0) strcpy(ime, token);
if(br==1) strcpy(prezime, token);
if(br==2)
{
ocena=atoi(token);
pr++;
suma=suma+ocena;
}
br++;
token=strtok(NULL, " ");
}
glava=dodaj(glava, ime, prezime, ocena);
}
return(glava);
}
void printaj(STUDENTI *glava)
{
if (glava==NULL)
{

return;
}
printf("%s %s %d\n", glava->ime, glava->prezime, glava->ocena);
printaj(glava->sledeci);
}
void prosek(STUDENTI *glava)
{
double suma=0.0;
double prosek=0.0;
int br=0;
STUDENTI *tmp=glava;
while(tmp!=NULL)
{
br++;
suma+=tmp->ocena;
tmp=tmp->sledeci;
}
prosek=suma/br;
printf("Prosek je: %f", prosek);
}