SpeedTest

Small C command-line project that:

• detects the user location
• finds the closest server from a local server list
• measures download and upload speed with libcurl
• can generate a server list enriched with latitude and longitude

Project layout

• main.c: entry point and CLI handling
• nest/speedtest.c: download and upload tests
• nest/servers.c: closest-server selection and location lookup
• nest/fetchcoords.c: Geoapify geocoding helpers
• nest/initservers.c: enriches the raw server list with coordinates
• nest/utils.c: shared file and curl buffer helpers
• speedtest_server_list.json: raw server list
• modified_speedtest_server_list.json: server list with coordinates

Dependencies

This project expects:

• GCC or Clang
• GNU Make
• libcurl development package
• cJSON development package
• pkg-config (recommended on Linux)

Linux package examples:

• Debian/Ubuntu:

sudo apt update
sudo apt install -y build-essential pkg-config libcurl4-openssl-dev libcjson-dev

• Fedora/RHEL:

sudo dnf install -y gcc make pkgconf-pkg-config libcurl-devel cjson-devel

• Arch Linux:

sudo pacman -S --needed base-devel pkgconf curl cjson

• Alpine:

sudo apk add build-base pkgconf curl-dev cjson-dev

Windows (MSYS2 MinGW64) example:

pacman -S --needed mingw-w64-x86_64-gcc mingw-w64-x86_64-curl mingw-w64-x86_64-cjson make

Build

make

If make is not on PATH in PowerShell, use the MSYS2 shell or run:

mingw32-make

On Linux, the output binary is:

./speedtest

On Windows, the output binary is:

./speedtest.exe

CLI options

• --make-json <file>: generate modified_speedtest_server_list.json from a server list JSON file.
• default run: when no --make-json is given, speedtest runs by default.
• --server, -s: detect location and print the best server only.
• --host <host>, -H <host>: target host for manual download-only or upload-only runs.
• --city <name> and --country <name>: override auto-detected location.
• --dstreams <count>: force stream count used by throughput tests.
• --download-only, -d: run only download test.
• --upload-only, -u: run only upload test.
• --verbose, -v: print verbose progress output.
• --help, -h: print usage.

Examples:

./speedtest --make-json speedtest_server_list.json
./speedtest
./speedtest --download-only --host speedtest.example.com
./speedtest --upload-only --host speedtest.example.com
./speedtest --server
./speedtest --city "Vilnius" --country "Lithuania"

Windows users can replace ./speedtest with ./speedtest.exe.

--make-json updates coordinates only when latitude/longitude are missing in input entries. Download and upload actions are always hard-stopped after 15 seconds.

Notes

• Download tests use a random4000x4000.jpg endpoint under /speedtest/.
• Upload tests use /speedtest/upload.php.
• Throughput rounds are time-based (not fixed-size): a short warm-up is run before measured throughput.
• Auto stream selection still uses ramp-up, but each ramp step is now measured by duration.
• Full automatic runs print a final summary after all actions complete.
• Individual actions print their results at the end of the selected action.
• Not every public speedtest host behaves the same way, so some servers may still reject one of the test endpoints.