WIP: shell arrows and backspace seem to work

r2axz · Nov 13, 2020 · 53577d4 · 53577d4
1 parent 8f3c53d
commit 53577d4
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Showing 3 changed files with 117 additions and 14 deletions.
diff --git a/cdc_shell.c b/cdc_shell.c
@@ -5,24 +5,127 @@
  */
 
 #include <string.h>
+#include <ctype.h>
+#include <stdlib.h>
 #include "cdc_shell.h"
 
-static char cmd_line[USB_SHELL_MAX_CMD_LINE_SIZE];
-static char *cmd_line_p = cmd_line;
+void cdc_shell_process_command(const char *cmd) {
 
-static const char *cdc_shell_banner =   "\r\n\r\n"
-                                        "*******************************\r\n"
-                                        "* Configuration Shell Started *\r\n"
-                                        "*******************************\t\n"
-                                        "\r\n";
-static const char *cdc_shell_prompt = ">";
+}
+
+static const char *cdc_shell_banner             = "\r\n\r\n"
+                                                  "*******************************\r\n"
+                                                  "* Configuration Shell Started *\r\n"
+                                                  "*******************************\t\n";
+static const char *cdc_shell_prompt             = "\r\n>";
+static const char *cdc_shell_err_too_long       = "\r\nError, command line is too long.";
+
+
+static const char *escape_cursor_forward        = "\033[C";
+static const char *escape_cursor_backward       = "\033[D";
+static const char *escape_clear_line_to_end     = "\033[0K";
+
+static char cmd_line_buf[USB_SHELL_MAX_CMD_LINE_SIZE];
+static char *cmd_line_cursor = cmd_line_buf;
+
+static void cdc_shell_clear_cmd_buf() {
+    cmd_line_cursor = cmd_line_buf;
+    memset(cmd_line_buf, 0, sizeof(cmd_line_buf));
+}
+
+static enum {
+    cdc_shell_idle,
+    cdc_shell_expects_lf,
+    cdc_shell_expects_csi,
+    cdc_shell_expects_csn
+} cdc_shell_state;
 
 void cdc_shell_init() {
-    cmd_line_p = cmd_line;
-    _cdc_shell_write(cdc_shell_banner, strlen(cdc_shell_banner));
-    _cdc_shell_write(cdc_shell_prompt, strlen(cdc_shell_prompt));
+    cdc_shell_clear_cmd_buf();
+    cdc_shell_state = cdc_shell_idle;
+    cdc_shell_write(cdc_shell_banner, strlen(cdc_shell_banner));
+    cdc_shell_write(cdc_shell_prompt, strlen(cdc_shell_prompt));
 }
 
+#define ANSI_CTRLSEQ_ESCAPE_CHAR    0x1B
+#define ANSI_CTRLSEQ_ESCAPE_CSI     0x5B
+#define ANSI_CTRLSEQ_CUF            0x43
+#define ANSI_CTRLSEQ_CUB            0x44
+
 void cdc_shell_process_input(const void *buf, size_t count) {
-    _cdc_shell_write(buf, count);
+    const char *sym = buf;
+    while (count--) {
+        switch (cdc_shell_state) {
+        case cdc_shell_expects_csn:
+            if (isdigit((int)*sym)) {
+                /* Ignore values for simplicity */
+                break;
+            } else {
+                if (*sym == ANSI_CTRLSEQ_CUF) {
+                    if (*cmd_line_cursor) {
+                        cmd_line_cursor++;
+                        cdc_shell_write(escape_cursor_forward, strlen(escape_cursor_forward));
+                    }
+                } else if (*sym == ANSI_CTRLSEQ_CUB) {
+                    if (cmd_line_cursor > cmd_line_buf) {
+                        cmd_line_cursor--;
+                        cdc_shell_write(escape_cursor_backward, strlen(escape_cursor_backward));
+                    }
+                }
+                cdc_shell_state = cdc_shell_idle;
+            }
+            break;
+        case cdc_shell_expects_csi:
+            if (*sym == ANSI_CTRLSEQ_ESCAPE_CSI) {
+                cdc_shell_state = cdc_shell_expects_csn;
+                break;
+            } else {
+                cdc_shell_state = cdc_shell_idle;
+                continue;
+            }
+        case cdc_shell_expects_lf:
+            cdc_shell_state = cdc_shell_idle;
+            if (*sym == '\n') {
+                break;
+            }
+        case cdc_shell_idle:
+            if (*sym == '\r' || *sym == '\n') {
+                cdc_shell_state = cdc_shell_expects_lf;
+                cdc_shell_process_command(cmd_line_buf);
+                cdc_shell_clear_cmd_buf();
+                cdc_shell_write(cdc_shell_prompt, strlen(cdc_shell_prompt));
+            } else if (*sym == ANSI_CTRLSEQ_ESCAPE_CHAR) {
+                cdc_shell_state = cdc_shell_expects_csi;
+            } else if (*sym == '\b') {
+                if (cmd_line_cursor > cmd_line_buf) {
+                    size_t n_symb;
+                    char n_symb_str[8];
+                    itoa(cmd_line_cursor - cmd_line_buf, n_symb_str, 10);
+                    cdc_shell_write("\033[", 2);
+                    cdc_shell_write(n_symb_str, strlen(n_symb_str));
+                    cdc_shell_write("D", 1);
+                    cdc_shell_write(escape_clear_line_to_end, strlen(escape_clear_line_to_end));
+                    cmd_line_cursor--;
+                    memmove(cmd_line_cursor, cmd_line_cursor+1, strlen(cmd_line_cursor));
+                    cdc_shell_write(cmd_line_buf, strlen(cmd_line_buf));
+                    n_symb = strlen(cmd_line_buf) - (cmd_line_cursor - cmd_line_buf);
+                    if (n_symb) {
+                        itoa(n_symb, n_symb_str, 10);
+                        cdc_shell_write("\033[", 2);
+                        cdc_shell_write(n_symb_str, strlen(n_symb_str));
+                        cdc_shell_write("D", 1);
+                    }
+                }
+            } else if (isprint((int)(*sym))) {
+                *cmd_line_cursor++ = *sym;
+                if ((cmd_line_cursor - cmd_line_buf) >= sizeof(cmd_line_buf)/sizeof(*cmd_line_buf)) {
+                    cdc_shell_clear_cmd_buf();
+                    cdc_shell_write(cdc_shell_err_too_long, strlen(cdc_shell_err_too_long));
+                    cdc_shell_write(cdc_shell_prompt, strlen(cdc_shell_prompt));
+                }
+                cdc_shell_write(sym, sizeof(*sym));
+            }
+        }
+        sym++;
+    }
 }
diff --git a/cdc_shell.h b/cdc_shell.h
@@ -11,7 +11,7 @@
 
 #define USB_SHELL_MAX_CMD_LINE_SIZE     0x100
 
-extern void _cdc_shell_write(const void *buf, size_t count);
+extern void cdc_shell_write(const void *buf, size_t count);
 
 void cdc_shell_init();
 void cdc_shell_process_input(const void *buf, size_t count);

diff --git a/usb_cdc.c b/usb_cdc.c
@@ -397,7 +397,7 @@ void usb_cdc_config_mode_process_tx() {
     }
 }
 
-void _cdc_shell_write(const void *buf, size_t count) {
+void cdc_shell_write(const void *buf, size_t count) {
     usb_cdc_state_t *cdc_state = &usb_cdc_states[USB_CDC_CONFIG_PORT];
     circ_buf_t *rx_buf = &cdc_state->rx_buf;
     while (count) {