Convert string to time_t

[pbrama]

I have a customer that supplied me with a text file that has some data and dates stored, apparently, as milliseconds since 01/01/1970 12:00a. I need to display the date/time in their application. I believe I can use the localtime routine but that requires the data passed to it to be in time_t format. I currently have it as a string.

One sample number stored in a string 1192034967000. How do I convert this to time_t so I can get the date/time conversion or is there a better way?

Thanks

[Cucumber]

The function sscanf does that, it let you assign variable values from a string.

[weaknessforcats]

time_t is just an unsigned int. You can convert from a string to time_t using a stringstream.

string str = "1192034967000";
time_t t;
stringstream ss;
ss << str;
ss >> t;
 

Be aware that time_t in its 32-but form is no good after Jan 18,2038.

[Banfa]

string str = "1192034967000";
time_t t;
stringstream ss;
ss << str;
ss >> t;
 

This wont work. You have forgotten that time_t is the time in seconds since 01/01/1970 12:00a but the number is the time in milliseconds. Worst if time_t is 32 bit because 1192034967000 takes more than 32 bits to represent it.

You need to drop the last 3 digits first and convert 1192034967 to a time_t.