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Using STD lib
Useful includes
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#include <stdlib.h> #include <string> // for string, substring #include <sstream> // for streamstring #include <iostream> // for cout, puts etc. #include <stdio.h> // for sprintf, printf( "%lf\n", accum ); #include <time.h> // time #include <fcntl.h> // open() #include <unistd.h> // read() #include <iomanip> // for setw using namespace std; // allows get rid of std:: prefix. |
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#include <time.h> // time
struct timespec start, stop;
int gettimeStatus = clock_gettime( CLOCK_REALTIME, &start );
printf ( "gettimeStatus: %d \n", gettimeStatus );
printf ( "start.tv_sec = %d start.tv_nsec = %d \n", start.tv_sec, start.tv_nsec );
gettimeStatus = clock_gettime( CLOCK_REALTIME, &stop );
printf ( " stop.tv_sec = %d stop.tv_nsec = %d \n", stop.tv_sec, stop.tv_nsec );
printf ( " dt_sec = %d dt_nsec = %d \n", stop.tv_sec - start.tv_sec,
stop.tv_nsec- start.tv_nsec);
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Input parameters parsification with getopt
getopt has potential problem: it does not detect the missing argument and pick-up the next available option as an argument...
RETURN VALUE:
- The getopt() function shall return the next option character specified on the command line.
- A colon ( ':' ) shall be returned if getopt() detects a missing argument and the first character of optstring was a colon ( ':' ).
- A question mark ( '?' ) shall be returned if getopt() encounters an option character not in optstring or detects a missing argument and the first character of optstring was not a colon ( ':' ).
- Otherwise, getopt() shall return -1 when all command line options are parsed.
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#include <getopt.h>
#include <stdio.h>
#include <iostream>
//===================
void usage(char* name) {
std::cout << "Usage: " << name << " [-a <aaa>] [-b <bbb>] [-c <ccc>] [-h] <p1> [<p2> [<p3> ...]] \n";
}
//===================
int main (int argc, char **argv)
{
char *avalue = NULL;
char *bvalue = NULL;
char *cvalue = NULL;
int index;
int c;
extern char *optarg;
extern int optind, optopt, opterr;
while ((c = getopt (argc, argv, ":a:b:c:h")) != -1)
switch (c)
{
case 'a':
avalue = optarg;
printf ("a: avalue = %s\n",avalue);
break;
case 'b':
bvalue = optarg;
printf ("b: bvalue = %s\n",bvalue);
break;
case 'c':
cvalue = optarg;
printf ("c: cvalue = %s\n",cvalue);
break;
case 'h':
printf ("h: ");
usage(argv[0]);
break;
case ':':
printf ("(:) Option -%c requires an argument.\n", optopt);
usage(argv[0]);
return EXIT_FAILURE;
case '?':
printf ("?: Option -%c requires an argument.\n", optopt);
usage(argv[0]);
return EXIT_FAILURE;
default:
printf ("default: You should not get here... option -%c .\n", optopt);
abort ();
}
printf ("End of options: avalue = %s, bvalue = %s, cvalue = %s\n",
avalue, bvalue, cvalue);
for (index = optind; index < argc; index++)
printf ("Non-option argument %s\n", argv[index]);
return EXIT_SUCCESS;
}
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