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/* SPDX-License-Identifier: BSD-3-Clause */
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <signal.h>
#include <string.h>
#include <time.h>
#include <termios.h>
#include <sys/ioctl.h>
#include <libgen.h>
/*** ANSI VT100 escape codes ***/
/* Colors */
#define ANSI_WHITEBG "\33[38;5;0;48;5;255m"
#define ANSI_RESET "\33[m"
/* Other escape codes */
#define ANSI_CLEARLINE "\33[2K\r"
#define ANSI_CLEARALL "\e[1;1H\e[2J"
/********** Common - used by both vi and ex **********/
int print_string(char *string);
int print_string(char *string) {
return write(STDOUT_FILENO, string, strlen(string));
}
/********************** ex mode **********************/
int _ex_main(int argc, char *argv[]);
int _ex_main(int argc, char *argv[]) {
print_string("<Not implemented>\n");
return 0; /* Not implemented yet. */
}
/********************** vi mode **********************/
struct cursor_pos {
/* Neat way to keep track of the cursor's position. */
unsigned int x;
unsigned int y;
};
int _vi_main(int argc, char *argv[]);
int _vi_set_cursor_pos(unsigned int x, unsigned int y);
int _vi_init(unsigned int lines, unsigned int columns,
char buffer[BUFSIZ], struct cursor_pos cposition, long int offset_position,
FILE *filstr);
void _vi_printUsage();
int _vi_print_buffer_line(char s[BUFSIZ], unsigned int numlines);
int _vi_main(int argc, char *argv[]) {
int argument, offset;
char cmd;
FILE *filstr;
char buffer[BUFSIZ];
struct sigaction signal_action;
struct termios oldattr, newattr;
struct winsize w;
struct cursor_pos cposition, fposition;
ioctl(STDOUT_FILENO, TIOCGWINSZ, &w);
unsigned int lines = w.ws_row - 1;
unsigned int columns = w.ws_col - 1;
while ((argument = getopt(argc, argv, "")) != -1) {
if (argument == '?') {
_vi_printUsage();
return 1;
}
}
argc -= optind;
argv += optind;
signal_action.sa_handler = SIG_IGN;
sigemptyset(&signal_action.sa_mask);
sigaction(SIGINT, &signal_action, NULL);
setvbuf(stdout, NULL, _IONBF, 0);
/* Initialise vi */
if (argv[0]) {
filstr = fopen(argv[0], "r+");
if (errno) {
if (errno != ENOENT)
return errno;
}
} _vi_init(lines, columns, buffer, cposition, offset, filstr);
for (;;) {
/* Get a character */
tcgetattr(0, &oldattr); /* Get previous terminal parameters */
newattr = oldattr;
newattr.c_lflag &= ~( ICANON | ECHO ); /* Disable ECHO and ICANON */
tcsetattr(0, TCSANOW, &newattr); /* Set net parameters */
cmd = getchar();
switch (cmd) {
/*********************** Moving the cursor ***********************/
case 'k': /* up */
if (fposition.y > 0) fposition.y--;
else break;
if (cposition.y != 1)
_vi_set_cursor_pos(cposition.x, (cposition.y = cposition.y - 1));
else if (fposition.y == 0) {
_vi_set_cursor_pos(1, 1);
print_string(ANSI_CLEARALL); /* Clear screen */
fposition.y--; /* Say, 118 */
for (unsigned int i = lines - 1 /* 79 */; i > 0; i--) {
_vi_print_buffer_line(buffer, fposition.y - i); /* 120 - 78 */
}
_vi_set_cursor_pos(cposition.x, cposition.y);
}
break;
case 'j': /* down */
if (cposition.y != (lines - 1) && fposition.y++)
_vi_set_cursor_pos(cposition.x, (cposition.y = cposition.y + 1));
else if (cposition.y == lines - 1) {
_vi_set_cursor_pos(1, 1);
print_string(ANSI_CLEARALL); /* Clear screen */
fposition.y++; /* Say, 120 */
for (unsigned int i = lines - 1 /* 79 */; i > 0; i--) {
_vi_print_buffer_line(buffer, fposition.y - i); /* 120 - 78 */
}
_vi_set_cursor_pos(cposition.x, cposition.y);
}
break;
case 'l': /* right */
if (cposition.x != columns && fposition.x++)
_vi_set_cursor_pos((cposition.x = cposition.x + 1), cposition.y);
break;
case 'h': /* left */
if (cposition.x != 1 && fposition.x--)
_vi_set_cursor_pos((cposition.x = cposition.x - 1), cposition.y);
break;
/************************* Command mode: *************************/
case ':':
_vi_set_cursor_pos(1, lines);
print_string(ANSI_CLEARLINE ":");
tcsetattr(0, TCSANOW, &oldattr); /* Restore old parameters */
cmd = getchar();
switch (cmd) {
case '\33':
_vi_set_cursor_pos(1, lines);
print_string(ANSI_CLEARLINE);
break;
case 'q':
print_string(ANSI_CLEARALL); /* Clear screen */
_vi_set_cursor_pos(1, 1); /* Reset the cursor position */
if (filstr) fclose(filstr);
return 0;
case '\n':
break;
default:
_vi_set_cursor_pos(1, lines);
print_string("unknown command");
break;
}
_vi_set_cursor_pos(cposition.x, cposition.y);
}
tcsetattr(0, TCSANOW, &oldattr); /* Restore old parameters */
}
return 0;
}
int _vi_init(unsigned int lines, unsigned int columns,
char buffer[BUFSIZ], struct cursor_pos cposition,
long int offset_position, FILE *filstr) {
int status = 0;
print_string(ANSI_CLEARALL); /* Clear screen */
_vi_set_cursor_pos(1, 1);
if (filstr) {
fread(buffer, BUFSIZ, 1, filstr);
//if (fgets(buffer, 4096, filstr) != NULL) {
// offset_position = ftell(filstr);
// fputs(buffer, stdout);
//}
for (unsigned int i = 0; i < lines - 1; i++)
_vi_print_buffer_line(buffer, i);
} else {
for (unsigned int i = 1; i < (lines ); i++)
fputs("~\n", stdout);
status = 2; /* No file */
} _vi_set_cursor_pos((cposition.x = 1), (cposition.y = 1));
return status;
}
int _vi_set_cursor_pos(unsigned int x, unsigned int y) {
return printf("\033[%u;%uH", (y), (x));
}
void _vi_printUsage() {
printf("Ferass' Base System. (%s)\n\n"
"Usage: vi [filename]\n"
"Visual editor.\n", VERSION);
}
int _vi_print_buffer_line(char s[BUFSIZ], unsigned int numlines) {
unsigned int lines_found, chars;
/* Search for <numlines> - 1 lines and skip them entirely. */
for (chars = 0, lines_found = 0;
s[chars] && lines_found < numlines; s[chars] == '\n' && lines_found++, chars++)
/* TODO: Use strchr(). */ ;
/* Print the last line found. */
for (; s[chars] && s[chars] != '\n'; chars++) putchar((int)s[chars])
/* TODO: Do not print character-by-character. */ ;
putchar((int)'\n');
return 0;
}
/************ main() ************/
int main(int argc, char *argv[]) {
if (!strcmp(basename(argv[0]), "ex")) return _ex_main(argc, argv);
else /* Default to vi */ return _vi_main(argc, argv);
return 0; /* Never reached. */
}
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