Add dn_seshc helper lib

Single-Header/dn_single_header.cpp

@@ -1,4 +1,4 @@
-// Generated by the DN single header generator 2026-07-15 09:59:54
+// Generated by the DN single header generator 2026-07-15 17:58:16
 
 // DN: Single header generator commented out => #if defined(_CLANGD)
 //   #define DN_WITH_TESTS 1

Single-Header/dn_single_header.h

@@ -1,4 +1,4 @@
-// Generated by the DN single header generator 2026-07-15 09:59:54
+// Generated by the DN single header generator 2026-07-15 17:58:16
 
 #if !defined(DN_H)
 #define DN_H
@@ -614,6 +614,7 @@
 #define DN_Min(a, b) (((a) < (b)) ? (a) : (b))
 #define DN_Clamp(val, lo, hi) DN_Max(DN_Min(val, hi), lo)
 #define DN_Squared(val) ((val) * (val))
+#define DN_ArgShift(ptr, size) ((size) ? ((size)--, *(ptr)++) : 0)
 
 #define DN_Swap(a, b) \
   do {                \

Source/Extra/dn_seshc.cpp

@@ -0,0 +1,115 @@
+#include "dn_seshc.h"
+
+DN_Str8 DN_SH_CLIOptionsStr8()
+{
+  DN_Str8 result = DN_Str8Lit(
+"SESHC OPTIONS (note all options must be set to activate Seshc):\n"
+"  --seshc-exe-path <path>          Path to the Seshc EXE file to invoke for sending messages\n"
+"  --seshc-account-secret <secret>  Specify the secret of the Session account to send a message\n"
+"                                   as (see --help on the Seshc EXE for more info)\n"
+"  --seshc-seed-node <url>          URL to the Session seed node for determining the nodes to\n"
+"                                   send the message to\n"
+"  --seshc-display-name <name>      Display name to send the message as\n"
+"  --seshc-recipient-pkey <name>    Recipient to send the message as (must be 0x05 prefixed, 0x\n"
+"                                   is optional)"
+  );
+  return result;
+}
+
+DN_SHCLIEatArgResult DN_SH_CLIEatArg(DN_SHCLIArgs *args, char const **arg_ptr, int arg_count)
+{
+  DN_SHCLIEatArgResult result = {};
+  result.arg_ptr           = arg_ptr;
+  result.arg_count         = arg_count;
+
+  DN_Str8 arg = {};
+  if (arg_count)
+    arg = DN_Str8FromCStr8(*result.arg_ptr);
+
+  // NOTE: Try handling the argument if we recognise it
+  {
+    if (!result.eaten && DN_Str8EqInsensitive(arg, DN_Str8Lit("--seshc-exe-path"))) {
+      (void)DN_ArgShift(result.arg_ptr, result.arg_count);
+      result.eaten   = true;
+      args->exe_path = DN_Str8FromCStr8(DN_ArgShift(result.arg_ptr, result.arg_count));
+
+      if (DN_OS_PathInfo(args->exe_path).type != DN_OSPathInfoType_File) {
+        result.error_msg = DN_Str8Lit("Seshc executable path does not point to a file");
+        result.error_arg = args->exe_path;
+        args->exe_path   = {};
+      }
+    }
+
+    if (!result.eaten && DN_Str8EqInsensitive(arg, DN_Str8Lit("--seshc-account-secret"))) {
+      (void)DN_ArgShift(result.arg_ptr, result.arg_count);
+      result.eaten         = true;
+      args->account_secret = DN_Str8FromCStr8(DN_ArgShift(result.arg_ptr, result.arg_count));
+    }
+
+    if (!result.eaten && DN_Str8EqInsensitive(arg, DN_Str8Lit("--seshc-seed-node"))) {
+      (void)DN_ArgShift(result.arg_ptr, result.arg_count);
+      result.eaten        = true;
+      args->seed_node_url = DN_Str8FromCStr8(DN_ArgShift(result.arg_ptr, result.arg_count));
+    }
+
+    if (!result.eaten && DN_Str8EqInsensitive(arg, DN_Str8Lit("--seshc-display-name"))) {
+      (void)DN_ArgShift(result.arg_ptr, result.arg_count);
+      result.eaten       = true;
+      args->display_name = DN_Str8FromCStr8(DN_ArgShift(result.arg_ptr, result.arg_count));
+    }
+
+    if (!result.eaten && DN_Str8EqInsensitive(arg, DN_Str8Lit("--seshc-recipient-pkey"))) {
+      (void)DN_ArgShift(result.arg_ptr, result.arg_count);
+      result.eaten         = true;
+      args->recipient_pkey = DN_Str8FromCStr8(DN_ArgShift(result.arg_ptr, result.arg_count));
+
+      DN_Str8 check = DN_Str8TrimHexPrefix(args->recipient_pkey);
+      if (!DN_Str8StartsWithSensitive(check, DN_Str8Lit("05"))) {
+        result.error_msg     = DN_Str8Lit("Seshc recipient public key does not have a 05 prefix");
+        result.error_arg     = args->recipient_pkey;
+        args->recipient_pkey = {};
+      }
+    }
+  }
+
+  if (args->seed_node_url.count && args->account_secret.count && args->exe_path.count && args->display_name.count && args->recipient_pkey.count)
+    args->valid = true;
+  return result;
+}
+
+bool DN_SH_CLIArgsSendDMFmt(DN_SHCLIArgs *cli_args, DN_Str8 sesh_pkey_hex, char const *fmt, ...)
+{
+  DN_TCScratch scratch = DN_TCScratchBeginArena(nullptr, 0);
+
+  va_list args;
+  va_start(args, fmt);
+  DN_Str8 msg = DN_Str8FromFmtVArena(&scratch.arena, fmt, args);
+  va_end(args);
+
+  DN_Str8 cmds[] = {
+      cli_args->exe_path,
+      DN_Str8Lit("--account-secret"),
+      cli_args->account_secret,
+      DN_Str8Lit("--seed-node-url"),
+      cli_args->seed_node_url,
+      DN_Str8Lit("--display-name"),
+      DN_Str8FromFmtArena(&scratch.arena, "\"%.*s\"", DN_Str8PrintFmt(cli_args->display_name)),
+      DN_Str8Lit("send"),
+      sesh_pkey_hex,
+      msg,
+  };
+
+  DN_Str8Slice cmd_line = {};
+  cmd_line.data         = cmds;
+  cmd_line.count        = DN_ArrayCountU(cmds);
+
+  DN_OSExecArgs   exec_args  = {};
+  exec_args.flags           |= DN_OSExecFlags_SaveOutput;
+  DN_OSExecResult exec       = DN_OS_Exec(cmd_line, &exec_args, &scratch.arena, nullptr);
+  DN_LogInfoF("OUT (exit code:%zu, os: %zu): %.*s", exec.exit_code, exec.os_error_code, DN_Str8PrintFmt(exec.stdout_text));
+  DN_LogInfoF("ERR: %.*s", DN_Str8PrintFmt(exec.stderr_text));
+  DN_TCScratchEnd(&scratch);
+
+  bool result = exec.os_error_code == 0 && exec.exit_code == 0;
+  return result;
+}

Source/Extra/dn_seshc.h

@@ -0,0 +1,36 @@
+#if !defined(DN_SESHC_H)
+#define DN_SESHC_H
+
+#if defined(_CLANGD)
+  #define DN_WITH_OS 1
+  #include "../dn.h"
+#endif
+
+struct DN_SHCLIArgs
+{
+  bool    valid;
+  DN_Str8 exe_path;
+  DN_Str8 account_secret;
+  DN_Str8 seed_node_url;
+  DN_Str8 display_name;
+  DN_Str8 recipient_pkey;
+};
+
+struct DN_SHCLIEatArgResult
+{
+  bool         eaten;
+  DN_Str8      error_msg; // Parsing error message. String is immutably stored in the data-segment w/ program lifetime.
+  DN_Str8      error_arg; // Argument that caused the parsing error
+  char const **arg_ptr;   // Next argument pointer that that the caller should proceed from
+  DN_USize     arg_count; // Next argument count that that the caller should assume
+};
+
+// NOTE: Seshc
+// Overview
+//   Helper library that provides some useful APIs for programatically calling the Seshc CLI
+//   executable to send messages from your C/C++ application.
+DN_Str8              DN_SH_CLIOptionsStr8  ();
+DN_SHCLIEatArgResult DN_SH_CLIEatArg       (DN_SHCLIArgs *args, char const **arg_ptr, int arg_count);
+bool                 DN_SH_CLIArgsSendDMFmt(DN_SHCLIArgs *cli_args, DN_Str8 sesh_pkey_hex, char const *fmt, ...);
+
+#endif // #if !defined(DN_SESHC_H)

Source/dn.h

@@ -612,6 +612,7 @@
 #define DN_Min(a, b) (((a) < (b)) ? (a) : (b))
 #define DN_Clamp(val, lo, hi) DN_Max(DN_Min(val, hi), lo)
 #define DN_Squared(val) ((val) * (val))
+#define DN_ArgShift(ptr, size) ((size) ? ((size)--, *(ptr)++) : 0)
 
 #define DN_Swap(a, b) \
   do {                \