What help with this Assembly language Subroutine, Basic Computer Science

Assignment Help:
Write an ARM subroutine which will extract a substring from a string. You will need to use the library routine malloc to allocate memory for the new string.

The subroutine signature is:
char * mysubstring( char string[], int start, int end ) ;

where char string[] is the string to extract the substring from; it is passed into the ARM routine as a pointer in a1 to the first element of the character (byte) array,
int start is the first character to extract from the string to the substring; it is passed into the ARM routine as a value in a2,
int end is the last character to extract from the string to the substring; it is passed into the ARM routine as a value in a3.
The return is a pointer to the new string.

#include
#include

extern char * mysubstring( char string[], int start, int end ) ;

int main( int argc, char * argv[] )
{
char tosub[] = "this is the string to substring" ;
char * result ; /* pointer to new string */

result = mysubstring( tosub, 12, 17 ) ;
printf( "String: %s\nSubstring: %s\n", tosub, result ) ;

exit( 0 ) ;

}

To use the library routine malloc you need to calculate the number of bytes of memory you are requesting, put that number in a1 and bl malloc. Upon return from the library routine a1 will have a pointer to the allocated memory.

You may assume that the start and end values are within the string and malloc returns a proper pointer value.

Related Discussions:- What help with this Assembly language Subroutine

Briefly explain the shutter speed, Question 1 Write a note on transition, ...

Question 1 Write a note on transition, transition types & Features Question 2 Describe the different types of lens used in film shooting Question 3 Briefly explain

Quotation in Python, Python allows single (''), double (") and triple (''''...

Python allows single (''), double (") and triple ('''''' or """) quotes to indicate string literals, as long as the similar type of quote starts and ends the string. The triple quo

Opening documents situated on different computers - network, Opening Docume...

Opening Documents Situated on Different Computers In order to work with documents situated on other computers, you need sufficient rights to access the folder in which it is

DBMS, what is the meaning of data definition

what is the meaning of data definition

Process killed, 1. What actions need to be taken when a program terminates ...

1. What actions need to be taken when a program terminates or a process is killed? What if that process destruction is not the consequence of normal termination, but rather is the

Qbasic, write a program of circle of any colour

write a program of circle of any colour

2. What benefits can a company gain by managing its , 2. What benefits can ...

2. What benefits can a company gain by managing its own information infrastructure and services?

Evolution of erp , Evolution of ERP  The origin of using computers for ...

Evolution of ERP  The origin of using computers for business, traces the following line of story. Originally, they were designed to support the repetitive and time consuming fu

Advantages and disadvantages of e-learning, Advantages and Disadvantages of...

Advantages and Disadvantages of E-Learning: Before we discuss about advantages and disadvantages of e-learning, you should know that e-learning is just another model for learn

Execute a command in operating system, Execute a command in operating syste...

Execute a command in operating system: In order to execute a command OS does the following steps:   It accepts a command from a user through mouse clicks or from t

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd