commit 0174f877eee2f83b1b9d399257849a5531ec93c1
parent 460105a7ba113eefa4c456a7135c049afe4dbd96
Author: night0721 <[email protected]>
Date: Thu, 8 Feb 2024 12:33:42 +0000
able to navigate by left and right arrow keys, and insert in middle of command
Diffstat:
| M | rush.c | | | 123 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---------------- |
1 file changed, 99 insertions(+), 24 deletions(-)
diff --git a/rush.c b/rush.c
@@ -32,7 +32,6 @@ void change_terminal_attribute(int option) {
char **setup_path_variable() {
char *envpath = getenv("PATH");
if (envpath == NULL) {
- // ?????
fprintf(stderr, "rush: PATH environment variable is missing\n");
exit(EXIT_FAILURE);
}
@@ -75,6 +74,7 @@ bool find_command(char **paths, char *command) {
}
while (*paths != NULL) {
char current_path[PATH_MAX];
+ current_path[0] = '\0';
sprintf(current_path, "%s/%s", *paths, command);
if (access(current_path, X_OK) == 0) {
// command is executable
@@ -89,12 +89,23 @@ bool find_command(char **paths, char *command) {
return false;
}
+void shiftleft(int chars) {
+ printf("\033[%dD", chars);
+}
+
+void shiftright(int chars) {
+ printf("\033[%dC", chars);
+}
+
char *readline(char **paths) {
int bufsize = RL_BUFSIZE;
int position = 0;
char *buffer = malloc(sizeof(char) * bufsize);
- int c;
+ bool moved = false;
+ bool backspaced = false;
+ bool navigated = false;
+ bool insertatmiddle = false;
if (!buffer) {
fprintf(stderr, "rush: Error allocating memory\n");
exit(EXIT_FAILURE);
@@ -102,17 +113,15 @@ char *readline(char **paths) {
buffer[0] = '\0';
while (1) {
- c = getchar(); // read a character
+ int c = getchar(); // read a character
int buf_len = strlen(buffer);
- if (buf_len > 0) {
- printf("\033[%ldD", strlen(buffer)); // move cursor to the beginning
- printf("\033[K"); // clear line to the right of cursor
- }
+
// check each character user has input
switch (c) {
case EOF:
exit(EXIT_SUCCESS);
- case 10: // enter/new line feed
+ case 10: {
+ // enter/new line feed
if (buf_len == 0) {
break;
}
@@ -121,12 +130,20 @@ char *readline(char **paths) {
for (int start = buf_len + 1; buffer[start] != '\0'; start++) {
buffer[start] = '\0';
}
- printf("%s\n", buffer); // print back the command in prompt
+ printf("\n"); // give space for response
save_command_history(buffer);
+ position = 0;
return buffer;
+ }
case 127: // backspace
if (buf_len >= 1) {
- buffer[buf_len - 1] = '\0'; // putting null character at last character to act as backspace
+ position--;
+ for (int i = position; i < buf_len; i++) {
+ // shift the buffer
+ buffer[i] = buffer[i + 1];
+ }
+ backspaced = true;
+ moved = false;
}
break;
case 27: // arrow keys comes at three characters, 27, 91, then 65-68
@@ -137,45 +154,90 @@ char *readline(char **paths) {
char *last_command = read_command(1);
if (last_command != NULL) {
strcpy(buffer, last_command);
- buf_len = strlen(buffer) - 1;
+ navigated = true;
}
+ moved = false;
break;
} else if (arrow_key == 66) { // down
char *last_command = read_command(0);
if (last_command != NULL) {
strcpy(buffer, last_command);
- buf_len = strlen(buffer) - 1;
+ navigated = true;
}
+ moved = false;
break;
} else if (arrow_key == 67) { // right
if (position < buf_len) {
- printf("\033[%dC", 1); // move cursor right
+ shiftright(1);
position++;
}
+ moved = true;
+ break;
} else if (arrow_key == 68) { // left
- if (position > 0) {
- printf("\033[%dD", 1); // move cursor right
+ if (position >= 1) {
+ shiftleft(1);
position--;
}
- } }
+ moved = true;
+ break;
+ }
+ }
default:
if (c > 31 && c < 127) {
if (position == buf_len) {
// Append character to the end of the buffer
buffer[buf_len] = c;
buffer[buf_len + 1] = '\0';
+ moved = false;
+ navigated = false;
} else {
// Insert character at the current position
memmove(&buffer[position + 1], &buffer[position], buf_len - position + 1);
buffer[position] = c;
- printf("\033[s"); // Save cursor position
- printf("%s", &buffer[position]); // Print from the current position
- printf("\033[u"); // Restore cursor position
- printf("\033[%dC", 1); // move cursor right by one place
+ shiftright(1);
+ insertatmiddle = true;
}
position++;
}
}
+ if (navigated && buf_len >= 1) {
+ if (position != 0) {
+ shiftleft(buf_len); // move cursor to the beginning
+ printf("\033[K"); // clear line to the right of cursor
+ }
+ }
+ buf_len = strlen(buffer);
+ if (moved) {
+ moved = false;
+ continue;
+ }
+ if (!navigated) {
+ if (position != buf_len) {
+ // not at normal place
+ if (backspaced) {
+ shiftleft(position + 1);
+ } else {
+ shiftleft(position); // move cursor to the beginning
+ }
+ } else if (buf_len > 1) {
+ if (backspaced) {
+ shiftleft(buf_len + 1); // move cursor to the beginning
+ } else {
+ shiftleft(buf_len - 1); // move cursor to the beginning
+ }
+ } else if (buf_len == 1) {
+ if (backspaced) {
+ shiftleft(2);
+ }
+ } else if (buf_len == 0) {
+ if (backspaced) {
+ shiftleft(1);
+ }
+ }
+ printf("\033[K"); // clear line to the right of cursor
+ } else {
+ navigated = false;
+ }
char *cmd_part = strchr(buffer, ' ');
char *command_without_arg = NULL;
int cmd_len = 0;
@@ -183,8 +245,8 @@ char *readline(char **paths) {
if (cmd_part != NULL) {
cmd_len = cmd_part - buffer;
- char *cmd = malloc(sizeof(char) * cmd_len + 1);
- command_without_arg = malloc(sizeof(char) * cmd_len + 1);
+ char *cmd = malloc(sizeof(char) * (cmd_len + 1));
+ command_without_arg = malloc(sizeof(char) * (cmd_len + 1));
if (cmd == NULL || command_without_arg == NULL) {
fprintf(stderr, "rush: Error allocating memory\n");
exit(EXIT_FAILURE);
@@ -196,6 +258,7 @@ char *readline(char **paths) {
cmd[cmd_len] = '\0';
command_without_arg[cmd_len] = '\0';
valid = find_command(paths, cmd);
+ free(cmd);
} else {
valid = find_command(paths, buffer);
}
@@ -214,11 +277,22 @@ char *readline(char **paths) {
printf("\x1b[38;2;243;139;168m%s\x1b[0m\x1b[38;2;255;255;255m%s\x1b[0m", command_without_arg, buffer); // print green as valid command, but only color the command, not the arguments
buffer -= cmd_len;
} else {
- printf("\x1b[38;2;243;139;168m%s\x1b[0m", buffer); // print red as sinvalid command
+ printf("\x1b[38;2;243;139;168m%s\x1b[0m", buffer); // print red as invalid command
}
}
- fflush(stdout);
+ free(command_without_arg);
+
+ if (backspaced) {
+ if (buf_len != position) {
+ shiftleft(buf_len - position);
+ }
+ backspaced = false;
+ }
+ if (insertatmiddle) {
+ shiftleft(buf_len - position); // move cursor back to where it was
+ insertatmiddle = false;
+ }
// If we have exceeded the buffer, reallocate.
if ((buf_len + 1) >= bufsize) {
bufsize += RL_BUFSIZE;
@@ -317,6 +391,7 @@ int main(int argc, char **argv) {
command_loop(paths);
// cleanup
+ free(paths);
change_terminal_attribute(0); // change back to default settings
return EXIT_SUCCESS;
}
