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Questions tagged [timeval]

56 questions
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choose between timeval and clock() to calculate elapsed time in C

I am using timeval as well as clock() function to see the time difference between 2 actions in my c program. Somehow timeval seems to give me the right amount of elapsed time in milliseconds where clock() gives very very less value. g_time =…
Gaurav Kumar
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Why isn't the timer running when I enter 1000 milliseconds as the interval?

I am working on a timer that gives timestamps for every interrupt at any amount of milliseconds the user wants it to shoot off at. struct itimerspec takes seconds and nanoseconds when using: it_interval (a member of the struct) I want to let the…
Mr.Longbottom
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Add or subtract an interval from a timeval

I've seen a number of questions / answers for subtracting two datetimes here but not one for adding or subtracting an interval to / from a timevalue. Add milliseconds to timeval C++ This asnwer does not result in a valid timeval structure. void…
James Newton
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How is it possible that tv_sec of both timeval structures are the same but subtracting them gives me a non zero value

timeval end_time; timeval Dbg_timer; The above time structures where initialized with gettimeofday() at some point. Below is how I calculated the time difference: long int elaspsed_time_s = end_time.tv_sec -…
African_king
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Obtain hardware timestamp

Is the time obtained by the pcap_next_ex function in libpcap the hard timestamp of the network card? If not, how to obtain the hard timestamp when the packet is received pcap_next_ex(pcap_t* p,struct pcap_pkthdr** pkt_header,const u_char** pkt_data)
Junsheng Shen
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IF function to calculate duration (Hours:Minutes:Seconds)

I use Importxml to extract the clock from a website that tells the date and time that the market will close ... Well, using the Now () function, I calculate the imported clock minus the current time. I converted the cell with the result of the…
Digital Farmer
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C - Convert between struct timeval and uint32_t to calculate elapsed time

I read a lot of posts on stackoverflow about endianness for network. For example, if I do something like this : struct timeval start_t gettimeofday(&start_t, NULL); Now , how can I be sure this kind of cast will work ? uint32_t receivedTime =…
jy95
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Use of struct timeval to set the response timeout on LibModbus

I am using the library LibModbus to connect with ADAM devices. I had some previous problem sending some commands to the device but setting a bigger response timeout it was fixed, this was in a previous version of the library. Now, I am using the…
Aday88
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Timeval structs: negative delay with libpcap

I'm trying to calculate delay from a captured packet to a previous packet, both coming from the same connection. I'm using a single linked list, each node corresponding to a connection; I discern packets coming from IP1 to IP2 from the ones coming…
elmazzun
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timeval to string (converting between the two)

I'm trying to pull the two components out of a timeval struct and place them into strings. I'm not having much luck with this. I've attempted casting and converting first to a long and then to a string. I need the most efficient way to do this. Any…
BSchlinker
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Better way to get absolute time?

Currently I'm trying to get absolute time to use with pthread_mutex_timedlock. I know I need to add the timeval from gettimeofday to the timespec and then add my arbitrary amount of time. The below works but it might overflow when multiplying with…
Brandon
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localtime() is showing 0 microseconds since 1970 as one hour

I have a timeval which is 0 seconds and 0 microseconds. I am therefore expecting zero hours: //Create a timeval representing 0 microseconds since 1970 struct timeval test; test.tv_sec = 0; test.tv_usec = 0; struct tm *nowtm2; time_t…
user997112
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warning: format '%06d' expects type 'int', but argument 5 has type '__suseconds_t'

I am using this code: struct timeval tv; time_t nowtime; struct tm *nowtm; char tmbuf[64], buf[64]; gettimeofday(&tv, NULL); nowtime = tv.tv_sec; nowtm = localtime(&nowtime); strftime(tmbuf, sizeof tmbuf, "%Y-%m-%d %H:%M:%S", nowtm); snprintf(buf,…
user997112
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timeval undefined when using windows.h and WIN32_LEAN_AND_MEAN

To avoid conflicts with winsock2.h, I want to wrap my include of windows.h with WIN32_LEAN_AND_MEAN (I undef it after windows.h so as not to interfere with applications that include my headers). Doing this causes timeval to be undefined when…
tjd
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Mismatch in timing

struct timeval start, end, duration; gettimeofday(&start, NULL); res = curl_easy_perform(curl); gettimeofday(&end, NULL); timersub(&end, &start, &duration); tm* startTime = localtime(&start.tv_sec); tm* endTime = localtime(&end.tv_sec); char…
Dave
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