Tomasz Pachołek - Blog about electronics

Name	Insulator	Maximum bandwidth, GHz	Is comply with	Description
Precision 1mm	Air, gap 1mm	110	only with 1mm	Much smaller than other
Precision 1,85mm	Air, gap 1,85mm	70	2,4mm	The outer thread size of the 1.85 and 2.4 connectors is bigger than SMA, 3.5, and 2.92. This makes the area of the outer conductor mating surface look very large compared to the relatively small air dielectric.
Precision 2,4mm	Air, gap 2,4mm	50	1,85mm	manufactured at Keysight
Precision 2,92mm (also named “K”)	Air, gap 2,92mm	40	3,5mm and SMA(regular)
Precision 3,5mm	Air, gap 3,5mmmm	34	2,92mm and SMA(regular)
SMA(regular)	PTFE(Teflon)	24	2,92mm and 3,5mm	Teflon dielectric, also in reverse polarity version named as RP-SMA

To download something from webside in C language, you can use curl library.
In linux you can install via:

sudo apt-get install libcurl4-openssl-dev

1	sudo apt-get install libcurl4-openssl-dev

Then write a program


#include&lt;stdio.h>
#include&lt;curl/curl.h>

int main(int argc, char **argv){
        //networking configuration lib
        CURL *curl;
        //file pointer
        FILE *fp;
        int result;
        //open file in wb write binary mode
        fp = fopen(argv[2], "wb");
        //handling networking - initialization
        curl = curl_easy_init();
        //configuration options, specify url which you want download
        curl_easy_setopt(curl, CURLOPT_URL, argv[1]);
        //write file
        curl_easy_setopt(curl, CURLOPT_WRITEDATA,fp);
        //check errors 404
        curl_easy_setopt(curl, CURLOPT_FAILONERROR, 1L);
        //download was succesfull or not
        result = curl_easy_perform(curl);

        if(result == CURLE_OK)
                printf("Download successful!\n");
        else
                printf("Error download: %s\n",curl_easy_strerror(result));
        //close file
        fclose(fp);
        //clean resources
        curl_easy_cleanup(curl);

}

#include<stdio.h>

#include<curl/curl.h>

int main(int argc, char **argv){

//networking configuration lib

CURL *curl;

//file pointer

FILE *fp;

int result;

//open file in wb write binary mode

fp = fopen(argv[2], "wb");

//handling networking - initialization

curl = curl_easy_init();

//configuration options, specify url which you want download

curl_easy_setopt(curl, CURLOPT_URL, argv[1]);

//write file

curl_easy_setopt(curl, CURLOPT_WRITEDATA,fp);

//check errors 404

curl_easy_setopt(curl, CURLOPT_FAILONERROR, 1L);

//download was succesfull or not

result = curl_easy_perform(curl);

if(result == CURLE_OK)

printf("Download successful!\n");

else

printf("Error download: %s\n",curl_easy_strerror(result));

//close file

fclose(fp);

//clean resources

curl_easy_cleanup(curl);

}

To use this code you must compile

sudo gcc urldownload.c -lcurl -o urldownload

1	sudo gcc urldownload.c -lcurl -o urldownload

And then run

sudo ./urldownload http://google.pl google.txt

1	sudo ./urldownload http://google.pl google.txt

When you have problem like “segmentation fault” you need use “sudo” before command.

Author: Tomasz Pachołek

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