[Query]: How will I use pkg-config with 'nob.c' ?

[pritam12426]

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

        Cmd cmd = {0};
        nob_cc(&cmd);
        nob_cc_flags(&cmd);
        nob_cmd_append(&cmd, "-std="C_STANDARD);

        // I wish to use pkg-config how will i ?

        nob_cc_output(&cmd, MAIN_BINARY_FILE);
        nob_cc_inputs(&cmd, MAIN_FUNCTION_FILE);
        if (!cmd_run(&cmd)) return 1;
        
        return 0;
}

[KillerxDBr]

You can redirect pkg-config output to a file or pipe and use it, thats what i do to create a dependency file in msvc with /showIncludes

[pritam12426]

can you pls give me the code example for it ? :)

[UnknownRedFoxDev]

I believe for the output to a file you do something akin to:

    Nob_Cmd cmd = {0};
    cmd_append(&cmd, "pkg-config");
    // cmd_append(&cmd, "[the dep]");
    // cmd_append(&cmd, "[the flags]");
    cmd_append(&cmd, "libcurl");
    cmd_append(&cmd, " --cflags");
    cmd_append(&cmd, " --libs");
    // if (!cmd_run(&cmd, .stdout_path="path-to-file")) return 1;
    if (!cmd_run(&cmd, .stdout_path="./libcurl-deps.txt")) return 1;

    String_Builder sb = {0};
    if (!read_entire_file("./libcurl-deps.txt", &sb)) return 1;
    String_View sv = sb_to_sv(sb);
     // it will give you a string like:
     // -DWITH_GZFILEOP -lcurl -lssl -lcrypto

    // cmds to compile
    cmd_append(&cmd, "gcc");
    cmd_append(&cmd, "-Wall");
    cmd_append(&cmd, "-Wextra");
   // ...
    while (sv.count > 0) {
        // And then you get each of the flags
        String_View dep_flag = sv_chop_by_delim(&sv, ' ');
        cmd_append(cmd, dep_flag);
    }
    // ...

This approach is kinda annoying since you leave files of your deps as you build. though you could delete them afterwards.
Moreover, you can create a helper function that gets the name of the dependency, and then automatically add the flags.

Although for the pipe approach I'm quite unsure on how the nob api works for it. But good luck nonetheless.

[KillerxDBr]

For pipes you need to use the deprecated api nob_cmd_run_sync_redirect or directly call nob__cmd_start_process
Edit: Add Win32 example

#define NOB_IMPLEMENTATION
#include "nob.h"

int main(void)
{
    Nob_Cmd cmd = {};
    Nob_String_Builder sb = {};

#ifdef _WIN32
    SECURITY_ATTRIBUTES sa = {};
    sa.nLength = sizeof(sa);
    sa.bInheritHandle = true; // Will not work without this

    HANDLE pipes[2];
    if (!CreatePipe(&pipes[0], &pipes[1], &sa, 0))
    {
        fprintf(stderr, "ERROR: CreatePipe: %s\n", nob_win32_error_message(GetLastError()));
        return 1;
    }
    nob_cmd_append(&cmd, "cmd", "/c", "echo pipe test");
#else
    int pipes[2];

    if (pipe(pipes) != 0)
    {
        fprintf(stderr, "ERROR: pipe: %s\n", strerror(errno));
        return 1;
    }

    nob_cmd_append(&cmd, "pkg-config", "ncurses", "--cflags", "--libs");
#endif

    // Use deprecated API
    if (!nob_cmd_run_sync_redirect(cmd, (Nob_Cmd_Redirect){.fdout = &pipes[1]})) return 1;
    // Or...
    // if (!nob_proc_wait(nob__cmd_start_process(cmd, NULL, &pipes[1], NULL))) return 1;

    while (true) {
        char tmp[256];
#ifdef _WIN32
        DWORD n = 0;
        // if you read exactly 256 bytes it will lock foverer on the next loop iteration
        if (!ReadFile(pipes[0], tmp, sizeof(tmp), &n, NULL))
        {
            fprintf(stderr, "ERROR: ReadFile: %s\n", nob_win32_error_message(GetLastError()));
            abort();
        }
        printf("Read %lu Bytes\n", n);
#else
        // if you read exactly 256 bytes it will lock foverer on the next loop iteration
        ssize_t n = read(pipes[0], tmp, sizeof(tmp));
        printf("Read %zd Bytes\n", n);
        if (n < 0)
        {
            fprintf(stderr, "ERROR: read: %s\n", strerror(errno));
            abort();
        }
#endif

        if (n != 0)
            nob_sb_append_buf(&sb, tmp, n);

        if (n < sizeof(tmp))
            break;
    }

#ifdef _WIN32
    CloseHandle(pipes[0]);
    CloseHandle(pipes[1]);
#else
    close(pipes[0]);
    close(pipes[1]);
#endif

    nob_sb_append_null(&sb);

    printf("Output: \"%s\"\n", sb.items);

    nob_sb_free(sb);
    nob_cmd_free(cmd);

    return 0;
}