print date on same line as other variables in printf

Question

I am trying to use system("date") in printf but I would like it on the same line and I do not know how to format it properly. Any suggestions.

printf("Temperature %.2f date %d \n", val, system("date"));

[`system()`](http://pubs.opengroup.org/onlinepubs/9699919799/functions/system.html) does not do what you appear to want it to do. — pmg, Oct 15 '18 at 13:03
perhaps you can use http://man7.org/linux/man-pages/man3/strftime.3.html — danglingpointer, Oct 15 '18 at 13:12
Or : [Get the current time in C](https://stackoverflow.com/questions/5141960/get-the-current-time-in-c) — Sander De Dycker, Oct 15 '18 at 13:14

score 2 · Answer 1 · answered Oct 15 '18 at 13:10

2

The system function returns the exit status of the given external command, which if successful will typically be 0. The specific command being run is outside of your process so you don't have too much control over what it outputs.

Rather than call an external command, there are functions you can call to get the information you want.

You need to first use the time function, which gives you the time in seconds since the UNIX epoch of 1970-01-01 00:00:00 UTC. Then pass this to the ctime function which gives you a text representation of the time:

time_t t = time(NULL);
printf("date is %s", ctime(&t));

answered Oct 15 '18 at 13:10

dbush

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Isn't it that `ctime()` suffixes its result with a new-line? ;-) – alk Oct 15 '18 at 13:18
@alk It sure does. And if you fix it by using `%.24s` (as is quite common), you've just introduced the dread y10k bug. – Steve Summit Oct 15 '18 at 15:22
@SteveSummit `y10k bug` I wouldn't care. :) – alk Oct 16 '18 at 13:13

print date on same line as other variables in printf

1 Answers1