libterm

commit 1b85f56e68ab878b749032a4533601bb38b9cfcc
Author: typable <contact@typable.dev>
Date:   Sun, 24 Mar 2024 12:56:36 +0100

Initial implementation

Diffstat:
A
README.md
 | 
3
+++
A
term.c
 | 
196
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
A
term.h
 | 
31
+++++++++++++++++++++++++++++++

3 files changed, 230 insertions(+), 0 deletions(-)
diff --git a/README.md b/README.md
@@ -0,0 +1,3 @@
+# libterm
+
+An easy-to-use terminal library
diff --git a/term.c b/term.c
@@ -0,0 +1,196 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <termios.h>
+#include <sys/ioctl.h>
+#include <errno.h>
+#include <stdarg.h>
+#include <poll.h>
+
+#include "term.h"
+
+struct termios termios;
+term_t term = { NULL, 0 };
+
+void term_panic(const char *str) {
+  write(STDOUT_FILENO, "\x1b[2J", 4);
+  write(STDOUT_FILENO, "\x1b[H", 3);
+  write(STDOUT_FILENO, "\x1b[?25h", 6);
+  perror(str);
+  exit(EXIT_FAILURE);
+}
+
+void term_disable_raw_mode() {
+  if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &termios) == -1) {
+    term_panic("tcsetattr");
+  }
+}
+
+void term_enable_raw_mode() {
+  if (tcgetattr(STDIN_FILENO, &termios) == -1) {
+    term_panic("tcgetattr");
+  }
+  atexit(term_disable_raw_mode);
+  struct termios raw = termios;
+  raw.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
+  raw.c_oflag &= ~(OPOST);
+  raw.c_cflag |= (CS8);
+  raw.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
+  raw.c_cc[VMIN] = 0;
+  raw.c_cc[VTIME] = 1;
+  if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw) == -1) {
+    term_panic("tcsetattr");
+  }
+}
+
+int term_read_cursor_pos(int *rows, int *cols) {
+  char buf[32];
+  unsigned int i = 0;
+  if (write(STDOUT_FILENO, "\x1b[6n", 4) != 4) {
+    return -1;
+  }
+  while (i < sizeof(buf) - 1) {
+    if (read(STDIN_FILENO, &buf[i], 1) != 1) {
+      break;
+    }
+    if (buf[i] == 'R') {
+      break;
+    }
+    i++;
+  }
+  buf[i] = '\0';
+  if (buf[0] != '\x1b' || buf[1] != '[') {
+    return -1;
+  }
+  if (sscanf(&buf[2], "%d;%d", rows, cols) != 2) {
+    return -1;
+  }
+  return -0;
+}
+
+int term_read_window_size(int *rows, int *cols) {
+  struct winsize ws;
+  if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) == -1 || ws.ws_col == 0) {
+    if (write(STDOUT_FILENO, "\x1b[999C\x1b[999B", 12) != 12) {
+      return -1;
+    }
+    return term_read_cursor_pos(rows, cols);
+  }
+  else {
+    *cols = ws.ws_col;
+    *rows = ws.ws_row;
+    return 0;
+  }
+}
+
+int term_poll_key(int timeout) {
+  struct pollfd fds[1];
+  fds[0].fd = STDIN_FILENO;
+  fds[0].events = POLLIN | POLLPRI;
+  if (poll(fds, 1, timeout)) {
+    return term_read_key();
+  }
+  return 0;
+}
+
+int term_read_key(void) {
+  int len;
+  char c;
+  while ((len = read(STDIN_FILENO, &c, 1)) != 1) {
+    if (len == -1 && errno != EAGAIN) {
+      term_panic("read");
+    }
+  }
+  if (c == '\x1b') {
+    char seq[3];
+    if (read(STDIN_FILENO, &seq[0], 1) != 1) {
+      return '\x1b';
+    }
+    if (read(STDIN_FILENO, &seq[1], 1) != 1) {
+      return '\x1b';
+    }
+    if (seq[0] == '[') {
+      if (seq[1] >= '0' && seq[1] <= '9') {
+        if (read(STDIN_FILENO, &seq[2], 1) != 1) {
+          return '\x1b';
+        }
+        if (seq[2] == '~') {
+          switch (seq[1]) {
+            case '1':
+              return HOME_KEY;
+            case '3':
+              return DEL_KEY;
+            case '4':
+              return END_KEY;
+            case '5':
+              return PAGE_UP;
+            case '6':
+              return PAGE_DOWN;
+            case '7':
+              return HOME_KEY;
+            case '8':
+              return END_KEY;
+          }
+        }
+      }
+      else {
+        switch (seq[1]) {
+          case 'A':
+            return ARROW_UP;
+          case 'B':
+            return ARROW_DOWN;
+          case 'C':
+            return ARROW_RIGHT;
+          case 'D':
+            return ARROW_LEFT;
+          case 'H':
+            return HOME_KEY;
+          case 'F':
+            return END_KEY;
+        }
+        return '\x1b';
+      }
+    }
+    else if (seq[0] == 'O') {
+      switch (seq[1]) {
+        case 'H':
+          return HOME_KEY;
+        case 'F':
+          return END_KEY;
+      }
+    }
+  }
+  return c;
+}
+
+void term_write(char *str) {
+  int str_len = strlen(str);
+  char *new_buffer = realloc(term.buffer, sizeof(char) * (term.len + str_len + 1));
+  if (new_buffer == NULL) {
+    fprintf(stderr, "Cannot realloc memory!\n");
+    return;
+  }
+  term.buffer = new_buffer;
+  memcpy(term.buffer + term.len, str, str_len);
+  term.len += str_len;
+  term.buffer[term.len] = '\0';
+}
+
+void term_writef(const char *format, ...) {
+  va_list args;
+  va_start(args, format);
+  char str[1000];
+  vsnprintf(str, sizeof(str), format, args);
+  term_write(str);
+  va_end(args);
+}
+
+void term_flush(void) {
+  if (term.len > 0) {
+    write(STDOUT_FILENO, term.buffer, term.len);
+    free(term.buffer);
+    term.buffer = NULL;
+    term.len = 0;
+  }
+}
diff --git a/term.h b/term.h
@@ -0,0 +1,31 @@
+#pragma once
+
+typedef enum {
+  ESC = 27,
+  BACKSPACE = 127,
+  ARROW_LEFT = 1000,
+  ARROW_RIGHT,
+  ARROW_UP,
+  ARROW_DOWN,
+  DEL_KEY,
+  HOME_KEY,
+  END_KEY,
+  PAGE_UP,
+  PAGE_DOWN,
+} keycode_t;
+
+typedef struct {
+  char *buffer;
+  int len;
+} term_t;
+
+void term_panic(const char *s);
+void term_disable_raw_mode(void);
+void term_enable_raw_mode(void);
+int term_read_cursor_pos(int *rows, int *cols);
+int term_read_window_size(int *rows, int *cols);
+int term_poll_key(int timeout);
+int term_read_key(void);
+void term_write(char *str);
+void term_writef(const char *format, ...);
+void term_flush(void);