Skip to main content

exit(), abort() and assert()


void exit ( int status );
exit() terminates the process normally.
status: Status value returned to the parent process. Generally, a status value of 0 or EXIT_SUCCESS indicates success, and any other value or the constant EXIT_FAILURE is used to indicate an error. 

exit() performs following operations.
* Flushes unwritten buffered data.
* Closes all open files.
* Removes temporary files.
* Returns an integer exit status to the operating system.
The C standard atexit() function can be used to customize exit() to perform additional actions at program termination.
Example use of exit.

/* exit example */
int main ()
FILE * pFile;
pFile = fopen ("myfile.txt", "r");
if (pFile == NULL)
printf ("Error opening file");
exit (1);
/* file operations here */
return 0;


void abort ( void );
Unlike exit() function, abort() may not close files that are open. It may also not delete temporary files and may not flush stream buffer. Also, it does not call functions registered with atexit().

This function actually terminates the process by raising a SIGABRT signal, and your program can include a handler to intercept this signal (see this).

So programs like below might not write “Geeks for Geeks” to “tempfile.txt”

int main()
FILE *fp = fopen("C:\\myfile.txt", "w");
if(fp == NULL)
printf("\n could not open file ");
fprintf(fp, "%s", "Geeks for Geeks");
/* ....... */
/* ....... */
/* Something went wrong so terminate here */
return 0;
If we want to make sure that data is written to files and/or buffers are flushed then we should either use exit() or include a signal handler for SIGABRT.


 void assert( int expression );
If expression evaluates to 0 (false), then the expression, sourcecode filename, and line number are sent to the standard error, and then abort() function is called.

 If the identifier NDEBUG (“no debug”) is defined with #define NDEBUG then the macro assert does nothing.
Common error outputting is in the form:
Assertion failed: expression, file filename, line line-number

void open_record(char *record_name)
assert(record_name != NULL);
/* Rest of code */
int main(void)


Popular posts from this blog

ORACLE 9i practice solutions

Created by BCL easyConverter SDK 3 (HTML Version)

Zoho Puzzle Questions With Answers

Measuring Time Logic Puzzle You are given with two ropes with variable width. However if we start burning both the ropes, they will burn at exactly same time i.e. an hour. The ropes are non-homogeneous in nature. You are asked to measure 45 minutes by using these two ropes.

How can you do it?

Please note that you can’t break the rope in half as it is being clearly stated that the ropes are non-homogeneous in nature.
Answer & Explanation Solution: 45 minutes

Explanation :
All you have to do is burn the first rope from both the ends and the second rope from one end only simultaneously. The first rope will burn in 30 minutes (half of an hour since we burned from both sides) while the other rope would have burnt half. At this moment, light the second rope from the other end as well. Where, the second rope would have taken half an hour more to burn completely, it will take just 15 minutes as we have lit it from the other end too.

Thus you have successfully calculated 30+15 = 45 minutes …

Hackerrank > SQL > Basic Select

01-Select All
Given a City table, whose fields are described as +-------------+----------+ | Field       | Type     | +-------------+----------+ | ID          | int(11)  | | Name        | char(35) | | CountryCode | char(3)  | | District    | char(20) | | Population  | int(11)  | +-------------+----------+
write a query that will fetch all columns for every row in the table.

My Solution
02-Select by ID
Given a City table, whose fields are described as