Write a program (in C) for the following man page : NAME mytouch - change the fi

Question

Write a program (in C) for the following man page :

NAME

mytouch - change the file timestamps

SYNOPSIS

mytouch FILE [SECONDS]

DESCRIPTION

Update the access and modification times of FILE to the current time.

EXAMPLES

mytouch foo.txt

sets the access and modification time of foo.txt to the current time if
foo.txt exists, creates it otherwise

mytouch foo.txt 1000000

sets the seconds since the epoch of the access and
modification time of foo.txt to 1000000

NOTES

·         Does not use any C++ specific code.

·         Does not prompt the user in any way.

·         Does not perform input validation.

mytouch foo.txt

sets the access and modification time of foo.txt to the current time if
foo.txt exists, creates it otherwise

mytouch foo.txt 1000000

sets the seconds since the epoch of the access and
modification time of foo.txt to 1000000

Explanation / Answer

#include <time.h>
#include <stdio.h>
#include <stdlib.h>
#include <utime.h>
#include <sys/stat.h>

int main(int argc, char *argv[]) {
const char *filename = argv[1];
FILE *fp = fopen(argv[1], "w");
close(fp);
int millis = time(NULL); /* set mtime to current time */
if (argc == 3)
{
millis = atoi(argv[2]);
}

struct stat foo;
time_t mtime;
struct utimbuf new_times;
  
stat(filename, &foo);
  
new_times.actime = millis; /* keep atime unchanged */
new_times.modtime = millis; /* set mtime to current time */
utime(filename, &new_times);

return 0;
}

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