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Diffstat (limited to 'movement/shell.c')
| -rw-r--r-- | movement/shell.c | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/movement/shell.c b/movement/shell.c new file mode 100644 index 00000000..8f146e59 --- /dev/null +++ b/movement/shell.c @@ -0,0 +1,220 @@ +/* + * MIT License + * + * Copyright (c) 2023 Edward Shin + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in all + * copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include "shell.h" + +#include <ctype.h> +#include <stdbool.h> +#include <stddef.h> +#include <stdint.h> +#include <stdio.h> +#include <string.h> + +#if __EMSCRIPTEN__ +#include <emscripten.h> +#endif + +#include "watch.h" +#include "shell_cmd_list.h" + +extern shell_command_t g_shell_commands[]; +extern const size_t g_num_shell_commands; + +#define NEWLINE "\r\n" + +#define SHELL_BUF_SZ (256) +#define SHELL_MAX_ARGS (16) +#define SHELL_PROMPT "swsh> " + +static char s_buf[SHELL_BUF_SZ] = {0}; +static size_t s_buf_len = 0; +// Pointer to the first invalid byte after the end of input. +static char *const s_buf_end = s_buf + SHELL_BUF_SZ; + +static char *prv_skip_whitespace(char *c) { + while (c >= s_buf && c < s_buf_end) { + if (*c == 0) { + return NULL; + } + if (!isspace((int) *c) != 0) { + return c; + } + c++; + } + return NULL; +} + +static char *prv_skip_non_whitespace(char *c) { + bool in_quote = false; + char quote_char; + while (c >= s_buf && c < s_buf_end) { + if (*c == 0) { + return NULL; + } + // Basic handling of quoted arguments. + // Can't handle recursive quotes. :( + if (in_quote || *c == '"' || *c == '\'') { + if (!in_quote) { + quote_char = *c; + in_quote = true; + } else if (*c == quote_char) { + in_quote = false; + } + } else { + if (isspace((int) *c) != 0) { + return c; + } + } + c++; + } + return NULL; +} + +static int prv_handle_command() { + char *argv[SHELL_MAX_ARGS] = {0}; + int argc = 0; + + char *c = &s_buf[0]; + s_buf[SHELL_BUF_SZ - 1] = '\0'; + + while (argc < SHELL_MAX_ARGS) { + // Skip contiguous whitespace + c = prv_skip_whitespace(c); + if (c == NULL) { + // Reached end of buffer + break; + } + + // We hit non-whitespace, set argv and argc for this upcoming argument + argv[argc++] = c; + + // Skip contiguous non-whitespace + c = prv_skip_non_whitespace(c); + if (c == NULL) { + // Reached end of buffer + break; + } + + // NULL-terminate this arg string and then increment. + *(c++) = '\0'; + } + + if (argc == 0) { + return -1; + } + + // Match against the command list + for (size_t i = 0; i < g_num_shell_commands; i++) { + if (!strcasecmp(g_shell_commands[i].name, argv[0])) { + // If argc isn't valid for this command, display its help instead. + if (((argc - 1) < g_shell_commands[i].min_args) || + ((argc - 1) > g_shell_commands[i].max_args)) { + if (g_shell_commands[i].help != NULL) { + printf(NEWLINE "%s" NEWLINE, g_shell_commands[i].help); + } + return -2; + } + // Call the command's callback + if (g_shell_commands[i].cb != NULL) { + printf(NEWLINE); + int ret = g_shell_commands[i].cb(argc, argv); + if (ret == -2) { + printf(NEWLINE "%s" NEWLINE, g_shell_commands[i].help); + } + return ret; + } + } + } + + return -1; +} + +void shell_task(void) { +#if __EMSCRIPTEN__ + // This is a terrible hack; ideally this should be handled deeper in the watch library. + // Alas, emscripten treats read() as something that should pop up an input box, so I + // wasn't able to implement this over there. I sense that this relates to read() being + // the wrong way to read data from USB (like we should be using fgets or something), but + // until I untangle that, this will have to do. + char *received_data = (char*)EM_ASM_INT({ + var len = lengthBytesUTF8(tx) + 1; + var s = _malloc(len); + stringToUTF8(tx, s, len); + return s; + }); + s_buf_len = min((SHELL_BUF_SZ - 2), strlen(received_data)); + memcpy(s_buf, received_data, s_buf_len); + free(received_data); + s_buf[s_buf_len++] = '\n'; + s_buf[s_buf_len++] = '\0'; + prv_handle_command(); + EM_ASM({ + tx = ""; + }); +#else + // Read one character at a time until we run out. + while (true) { + if (s_buf_len >= (SHELL_BUF_SZ - 1)) { + printf(NEWLINE "Command too long, clearing."); + printf(NEWLINE SHELL_PROMPT); + s_buf_len = 0; + break; + } + + int c = getchar(); + + if (c < 0) { + // Nothing left to read, we're done. + break; + } + + if (c == '\b') { + // Handle backspace character. + // We need to emit a backspace, overwrite the character on the + // screen with a space, and then backspace again to move the cursor. + if (s_buf_len > 0) { + printf("\b \b"); + s_buf_len--; + } + continue; + } else if (c != '\n' && c != '\r') { + // Print regular characters to the screen. + putchar(c); + } + + s_buf[s_buf_len] = c; + + if (c == '\n' || c == '\r') { + // Newline! Handle the command. + s_buf[s_buf_len+1] = '\0'; + (void) prv_handle_command(); + s_buf_len = 0; + printf(NEWLINE SHELL_PROMPT); + break; + } else { + s_buf_len++; + } + } +#endif +} |