Only escape prompts when used with `-e` (#1311)

examples/common.cpp

@@ -66,35 +66,33 @@ int32_t get_num_physical_cores() {
     return n_threads > 0 ? (n_threads <= 4 ? n_threads : n_threads / 2) : 4;
 }
 
-std::string process_escapes(const char* input) {
-    std::string output;
+void process_escapes(std::string& input) {
+    std::size_t input_len = input.length();
+    std::size_t output_idx = 0;
 
-    if (input != nullptr) {
-        std::size_t input_len = std::strlen(input);
-        output.reserve(input_len);
-
-        for (std::size_t i = 0; i < input_len; ++i) {
-            if (input[i] == '\\' && i + 1 < input_len) {
-                switch (input[++i]) {
-                    case 'n':  output.push_back('\n'); break;
-                    case 't':  output.push_back('\t'); break;
-                    case '\'': output.push_back('\''); break;
-                    case '\"': output.push_back('\"'); break;
-                    case '\\': output.push_back('\\'); break;
-                    default:   output.push_back('\\');
-                               output.push_back(input[i]); break;
-                }
-            } else {
-                output.push_back(input[i]);
+    for (std::size_t input_idx = 0; input_idx < input_len; ++input_idx) {
+        if (input[input_idx] == '\\' && input_idx + 1 < input_len) {
+            switch (input[++input_idx]) {
+                case 'n':  input[output_idx++] = '\n'; break;
+                case 'r':  input[output_idx++] = '\r'; break;
+                case 't':  input[output_idx++] = '\t'; break;
+                case '\'': input[output_idx++] = '\''; break;
+                case '\"': input[output_idx++] = '\"'; break;
+                case '\\': input[output_idx++] = '\\'; break;
+                default:   input[output_idx++] = '\\';
+                           input[output_idx++] = input[input_idx]; break;
             }
+        } else {
+            input[output_idx++] = input[input_idx];
         }
     }
 
-    return output;
+    input.resize(output_idx);
 }
 
 bool gpt_params_parse(int argc, char ** argv, gpt_params & params) {
     bool invalid_param = false;
+    bool escape_prompt = false;
     std::string arg;
     gpt_params default_params;
 
@@ -118,7 +116,9 @@ bool gpt_params_parse(int argc, char ** argv, gpt_params & params) {
                 invalid_param = true;
                 break;
             }
-            params.prompt = process_escapes(argv[i]);
+            params.prompt = argv[i];
+        } else if (arg == "-e") {
+            escape_prompt = true;
         } else if (arg == "--session") {
             if (++i >= argc) {
                 invalid_param = true;
@@ -335,6 +335,9 @@ bool gpt_params_parse(int argc, char ** argv, gpt_params & params) {
         gpt_print_usage(argc, argv, default_params);
         exit(1);
     }
+    if (escape_prompt) {
+        process_escapes(params.prompt);
+    }
 
     return true;
 }
@@ -355,6 +358,7 @@ void gpt_print_usage(int /*argc*/, char ** argv, const gpt_params & params) {
     fprintf(stderr, "  -t N, --threads N     number of threads to use during computation (default: %d)\n", params.n_threads);
     fprintf(stderr, "  -p PROMPT, --prompt PROMPT\n");
     fprintf(stderr, "                        prompt to start generation with (default: empty)\n");
+    fprintf(stderr, "  -e                    process prompt escapes sequences (\\n, \\r, \\t, \\', \\\", \\\\)\n");
     fprintf(stderr, "  --session FNAME       file to cache model state in (may be large!) (default: none)\n");
     fprintf(stderr, "  --random-prompt       start with a randomized prompt.\n");
     fprintf(stderr, "  --in-prefix STRING    string to prefix user inputs with (default: empty)\n");

examples/main/README.md

@@ -34,13 +34,18 @@ For an interactive experience, try this command:
 #### Unix-based systems (Linux, macOS, etc.):
 
 ```bash
-./main -m models/7B/ggml-model.bin -n -1 --color -r "User:" --in-prefix " " --prompt 'User: Hi\nAI: Hello. I am an AI chatbot. Would you like to talk?\nUser: Sure!\nAI: What would you like to talk about?\nUser:'
+./main -m models/7B/ggml-model.bin -n -1 --color -r "User:" --in-prefix " " \
+'User: Hi
+AI: Hello. I am an AI chatbot. Would you like to talk?
+User: Sure!
+AI: What would you like to talk about?
+User:'
 ```
 
 #### Windows:
 
 ```powershell
-main.exe -m models\7B\ggml-model.bin -n -1 --color -r "User:" --in-prefix " " --prompt "User: Hi\nAI: Hello. I am an AI chatbot. Would you like to talk?\nUser: Sure!\nAI: What would you like to talk about?\nUser:"
+main.exe -m models\7B\ggml-model.bin -n -1 --color -r "User:" --in-prefix " " -e --prompt "User: Hi\nAI: Hello. I am an AI chatbot. Would you like to talk?\nUser: Sure!\nAI: What would you like to talk about?\nUser:"
 ```
 
 The following command generates "infinite" text from a starting prompt (you can use `Ctrl-C` to stop it):