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txt42.c
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#define TXT42_VERSION "0.0.1"
#ifdef __linux__
#define _POSIX_C_SOURCE 200809L
#endif
#include <termios.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <ctype.h>
#include <time.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <unistd.h>
#include <stdarg.h>
#include <fcntl.h>
#include <signal.h>
/* Syntax highlight types */
#define HL_NORMAL 0
#define HL_NONPRINT 1
#define HL_COMMENT 2
#define HL_MLCOMMENT 3
#define HL_KEYWORD1 4
#define HL_KEYWORD2 5
#define HL_STRING 6
#define HL_NUMBER 7
#define HL_MATCH 8 /* Search match. */
#define HL_HIGHLIGHT_STRINGS (1 << 0)
#define HL_HIGHLIGHT_NUMBERS (1 << 1)
struct editorSyntax
{
char **filematch;
char **keywords;
char singleline_comment_start[2];
char multiline_comment_start[3];
char multiline_comment_end[3];
int flags;
};
/* This structure represents a single line of the file we are editing. */
typedef struct erow
{
int idx; /* Row index in the file, zero-based. */
int size; /* Size of the row, excluding the null term. */
int rsize; /* Size of the rendered row. */
char *chars; /* Row content. */
char *render; /* Row content "rendered" for screen (for TABs). */
unsigned char *hl; /* Syntax highlight type for each character in render.*/
int hl_oc; /* Row had open comment at end in last syntax highlight
check. */
} erow;
typedef struct hlcolor
{
int r, g, b;
} hlcolor;
/* editor config */
struct editorConfig
{
int cx, cy; /* Cursor x and y position in characters */
int rowoff; /* Offset of row displayed. */
int coloff; /* Offset of column displayed. */
int screenrows; /* Number of rows that we can show */
int screencols; /* Number of cols that we can show */
int numrows; /* Number of rows */
int rawmode; /* Is terminal raw mode enabled? */
erow *row; /* Rows */
int dirty; /* File modified but not saved. */
char *filename; /* Currently open filename */
char statusmsg[80];
time_t statusmsg_time;
struct editorSyntax *syntax; /* Current syntax highlight, or NULL. */
};
static struct editorConfig E;
enum KEY_ACTION
{
KEY_NULL = 0, /* NULL */
CTRL_C = 3, /* Ctrl-c */
CTRL_D = 4, /* Ctrl-d */
CTRL_F = 6, /* Ctrl-f */
CTRL_H = 8, /* Ctrl-h */
TAB = 9, /* Tab */
CTRL_L = 12, /* Ctrl+l */
ENTER = 13, /* Enter */
CTRL_Q = 17, /* Ctrl-q */
CTRL_S = 19, /* Ctrl-s */
CTRL_U = 21, /* Ctrl-u */
ESC = 27, /* Escape */
BACKSPACE = 127, /* Backspace */
/* The following are just soft codes, not really reported by the
* terminal directly. */
ARROW_LEFT = 1000,
ARROW_RIGHT,
ARROW_UP,
ARROW_DOWN,
DEL_KEY,
HOME_KEY,
END_KEY,
PAGE_UP,
PAGE_DOWN
};
void editorSetStatusMessage(const char *fmt, ...);
/* C / C++ */
char *C_HL_extensions[] = {".c", ".h", ".cpp", ".hpp", ".cc", NULL};
char *C_HL_keywords[] = {
/* C Keywords */
"auto", "break", "case", "continue", "default", "do", "else", "enum",
"extern", "for", "goto", "if", "register", "return", "sizeof", "static",
"struct", "switch", "typedef", "union", "volatile", "while", "NULL",
/* C++ Keywords */
"alignas", "alignof", "and", "and_eq", "asm", "bitand", "bitor", "class",
"compl", "constexpr", "const_cast", "deltype", "delete", "dynamic_cast",
"explicit", "export", "false", "friend", "inline", "mutable", "namespace",
"new", "noexcept", "not", "not_eq", "nullptr", "operator", "or", "or_eq",
"private", "protected", "public", "reinterpret_cast", "static_assert",
"static_cast", "template", "this", "thread_local", "throw", "true", "try",
"typeid", "typename", "virtual", "xor", "xor_eq",
/* C types */
"int|", "long|", "double|", "float|", "char|", "unsigned|", "signed|",
"void|", "short|", "auto|", "const|", "bool|", NULL};
/* Here we define an array of syntax highlights by extensions, keywords,
* comments delimiters and flags. */
struct editorSyntax HLDB[] = {
{/* C / C++ */
C_HL_extensions,
C_HL_keywords,
"//", "/*", "*/",
HL_HIGHLIGHT_STRINGS | HL_HIGHLIGHT_NUMBERS}};
#define HLDB_ENTRIES (sizeof(HLDB) / sizeof(HLDB[0]))
/* ======================= Low level terminal handling ====================== */
static struct termios orig_termios; /* In order to restore at exit.*/
void disableRawMode(int fd)
{
/* Don't even check the return value as it's too late. */
if (E.rawmode)
{
tcsetattr(fd, TCSAFLUSH, &orig_termios);
E.rawmode = 0;
}
}
/* Called at exit to avoid remaining in raw mode. */
void editorAtExit(void)
{
disableRawMode(STDIN_FILENO);
}
/* Raw mode: 1960 magic shit. */
int enableRawMode(int fd)
{
struct termios raw;
if (E.rawmode)
return 0; /* Already enabled. */
if (!isatty(STDIN_FILENO))
goto fatal;
atexit(editorAtExit);
if (tcgetattr(fd, &orig_termios) == -1)
goto fatal;
raw = orig_termios; /* modify the original mode */
/* input modes: no break, no CR to NL, no parity check, no strip char,
* no start/stop output control. */
raw.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
/* output modes - disable post processing */
raw.c_oflag &= ~(OPOST);
/* control modes - set 8 bit chars */
raw.c_cflag |= (CS8);
/* local modes - choing off, canonical off, no extended functions,
* no signal chars (^Z,^C) */
raw.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
/* control chars - set return condition: min number of bytes and timer. */
raw.c_cc[VMIN] = 0; /* Return each byte, or zero for timeout. */
raw.c_cc[VTIME] = 1; /* 100 ms timeout (unit is tens of second). */
/* put terminal in raw mode after flushing */
if (tcsetattr(fd, TCSAFLUSH, &raw) < 0)
goto fatal;
E.rawmode = 1;
return 0;
fatal:
errno = ENOTTY;
return -1;
}
/* Read a key from the terminal put in raw mode, trying to handle
* escape sequences. */
int editorReadKey(int fd)
{
int nread;
char c, seq[3];
while ((nread = read(fd, &c, 1)) == 0)
;
if (nread == -1)
exit(1);
while (1)
{
switch (c)
{
case ESC: /* escape sequence */
/* If this is just an ESC, we'll timeout here. */
if (read(fd, seq, 1) == 0)
return ESC;
if (read(fd, seq + 1, 1) == 0)
return ESC;
/* ESC [ sequences. */
if (seq[0] == '[')
{
if (seq[1] >= '0' && seq[1] <= '9')
{
/* Extended escape, read additional byte. */
if (read(fd, seq + 2, 1) == 0)
return ESC;
if (seq[2] == '~')
{
switch (seq[1])
{
case '3':
return DEL_KEY;
case '5':
return PAGE_UP;
case '6':
return PAGE_DOWN;
}
}
}
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;
}
}
}
/* ESC O sequences. */
else if (seq[0] == 'O')
{
switch (seq[1])
{
case 'H':
return HOME_KEY;
case 'F':
return END_KEY;
}
}
break;
default:
return c;
}
}
}
/* Use the ESC [6n escape sequence to query the horizontal cursor position
* and return it. On error -1 is returned, on success the position of the
* cursor is stored at *rows and *cols and 0 is returned. */
int getCursorPosition(int ifd, int ofd, int *rows, int *cols)
{
char buf[32];
unsigned int i = 0;
/* Report cursor location */
if (write(ofd, "\x1b[6n", 4) != 4)
return -1;
/* Read the response: ESC [ rows ; cols R */
while (i < sizeof(buf) - 1)
{
if (read(ifd, buf + i, 1) != 1)
break;
if (buf[i] == 'R')
break;
i++;
}
buf[i] = '\0';
/* Parse it. */
if (buf[0] != ESC || buf[1] != '[')
return -1;
if (sscanf(buf + 2, "%d;%d", rows, cols) != 2)
return -1;
return 0;
}
/* Try to get the number of columns in the current terminal. If the ioctl()
* call fails the function will try to query the terminal itself.
* Returns 0 on success, -1 on error. */
int getWindowSize(int ifd, int ofd, int *rows, int *cols)
{
struct winsize ws;
if (ioctl(1, TIOCGWINSZ, &ws) == -1 || ws.ws_col == 0)
{
/* ioctl() failed. Try to query the terminal itself. */
int orig_row, orig_col, retval;
/* Get the initial position so we can restore it later. */
retval = getCursorPosition(ifd, ofd, &orig_row, &orig_col);
if (retval == -1)
goto failed;
/* Go to right/bottom margin and get position. */
if (write(ofd, "\x1b[999C\x1b[999B", 12) != 12)
goto failed;
retval = getCursorPosition(ifd, ofd, rows, cols);
if (retval == -1)
goto failed;
/* Restore position. */
char seq[32];
snprintf(seq, 32, "\x1b[%d;%dH", orig_row, orig_col);
if (write(ofd, seq, strlen(seq)) == -1)
{
/* Can't recover... */
}
return 0;
}
else
{
*cols = ws.ws_col;
*rows = ws.ws_row;
return 0;
}
failed:
return -1;
}
/* ====================== Syntax highlight color scheme ==================== */
int is_separator(int c)
{
return c == '\0' || isspace(c) || strchr(",.()+-/*=~%[];", c) != NULL;
}
/* Return true if the specified row last char is part of a multi line comment
* that starts at this row or at one before, and does not end at the end
* of the row but spawns to the next row. */
int editorRowHasOpenComment(erow *row)
{
if (row->hl && row->rsize && row->hl[row->rsize - 1] == HL_MLCOMMENT &&
(row->rsize < 2 || (row->render[row->rsize - 2] != '*' ||
row->render[row->rsize - 1] != '/')))
return 1;
return 0;
}
/* Set every byte of row->hl (that corresponds to every character in the line)
* to the right syntax highlight type (HL_* defines). */
void editorUpdateSyntax(erow *row)
{
row->hl = realloc(row->hl, row->rsize);
memset(row->hl, HL_NORMAL, row->rsize);
if (E.syntax == NULL)
return; /* No syntax, everything is HL_NORMAL. */
int i, prev_sep, in_string, in_comment;
char *p;
char **keywords = E.syntax->keywords;
char *scs = E.syntax->singleline_comment_start;
char *mcs = E.syntax->multiline_comment_start;
char *mce = E.syntax->multiline_comment_end;
/* Point to the first non-space char. */
p = row->render;
i = 0; /* Current char offset */
while (*p && isspace(*p))
{
p++;
i++;
}
prev_sep = 1; /* Tell the parser if 'i' points to start of word. */
in_string = 0; /* Are we inside "" or '' ? */
in_comment = 0; /* Are we inside multi-line comment? */
/* If the previous line has an open comment, this line starts
* with an open comment state. */
if (row->idx > 0 && editorRowHasOpenComment(&E.row[row->idx - 1]))
in_comment = 1;
while (*p)
{
/* Handle // comments. */
if (prev_sep && *p == scs[0] && *(p + 1) == scs[1])
{
/* From here to end is a comment */
memset(row->hl + i, HL_COMMENT, row->size - i);
return;
}
/* Handle multi line comments. */
if (in_comment)
{
row->hl[i] = HL_MLCOMMENT;
if (*p == mce[0] && *(p + 1) == mce[1])
{
row->hl[i + 1] = HL_MLCOMMENT;
p += 2;
i += 2;
in_comment = 0;
prev_sep = 1;
continue;
}
else
{
prev_sep = 0;
p++;
i++;
continue;
}
}
else if (*p == mcs[0] && *(p + 1) == mcs[1])
{
row->hl[i] = HL_MLCOMMENT;
row->hl[i + 1] = HL_MLCOMMENT;
p += 2;
i += 2;
in_comment = 1;
prev_sep = 0;
continue;
}
/* Handle "" and '' */
if (in_string)
{
row->hl[i] = HL_STRING;
if (*p == '\\')
{
row->hl[i + 1] = HL_STRING;
p += 2;
i += 2;
prev_sep = 0;
continue;
}
if (*p == in_string)
in_string = 0;
p++;
i++;
continue;
}
else
{
if (*p == '"' || *p == '\'')
{
in_string = *p;
row->hl[i] = HL_STRING;
p++;
i++;
prev_sep = 0;
continue;
}
}
/* Handle non printable chars. */
if (!isprint(*p))
{
row->hl[i] = HL_NONPRINT;
p++;
i++;
prev_sep = 0;
continue;
}
/* Handle numbers */
if ((isdigit(*p) && (prev_sep || row->hl[i - 1] == HL_NUMBER)) ||
(*p == '.' && i > 0 && row->hl[i - 1] == HL_NUMBER))
{
row->hl[i] = HL_NUMBER;
p++;
i++;
prev_sep = 0;
continue;
}
/* Handle keywords and lib calls */
if (prev_sep)
{
int j;
for (j = 0; keywords[j]; j++)
{
int klen = strlen(keywords[j]);
int kw2 = keywords[j][klen - 1] == '|';
if (kw2)
klen--;
if (!memcmp(p, keywords[j], klen) &&
is_separator(*(p + klen)))
{
/* Keyword */
memset(row->hl + i, kw2 ? HL_KEYWORD2 : HL_KEYWORD1, klen);
p += klen;
i += klen;
break;
}
}
if (keywords[j] != NULL)
{
prev_sep = 0;
continue; /* We had a keyword match */
}
}
/* Not special chars */
prev_sep = is_separator(*p);
p++;
i++;
}
/* Propagate syntax change to the next row if the open commen
* state changed. This may recursively affect all the following rows
* in the file. */
int oc = editorRowHasOpenComment(row);
if (row->hl_oc != oc && row->idx + 1 < E.numrows)
editorUpdateSyntax(&E.row[row->idx + 1]);
row->hl_oc = oc;
}
/* Maps syntax highlight token types to terminal colors. */
int editorSyntaxToColor(int hl)
{
switch (hl)
{
case HL_COMMENT:
case HL_MLCOMMENT:
return 36; /* cyan */
case HL_KEYWORD1:
return 33; /* yellow */
case HL_KEYWORD2:
return 32; /* green */
case HL_STRING:
return 35; /* magenta */
case HL_NUMBER:
return 31; /* red */
case HL_MATCH:
return 34; /* blu */
default:
return 37; /* white */
}
}
/* Select the syntax highlight scheme depending on the filename,
* setting it in the global state E.syntax. */
void editorSelectSyntaxHighlight(char *filename)
{
for (unsigned int j = 0; j < HLDB_ENTRIES; j++)
{
struct editorSyntax *s = HLDB + j;
unsigned int i = 0;
while (s->filematch[i])
{
char *p;
int patlen = strlen(s->filematch[i]);
if ((p = strstr(filename, s->filematch[i])) != NULL)
{
if (s->filematch[i][0] != '.' || p[patlen] == '\0')
{
E.syntax = s;
return;
}
}
i++;
}
}
}
/* ======================= Editor rows implementation ======================= */
/* Update the rendered version and the syntax highlight of a row. */
void editorUpdateRow(erow *row)
{
unsigned int tabs = 0, nonprint = 0;
int j, idx;
/* Create a version of the row we can directly print on the screen,
* respecting tabs, substituting non printable characters with '?'. */
free(row->render);
for (j = 0; j < row->size; j++)
if (row->chars[j] == TAB)
tabs++;
unsigned long long allocsize =
(unsigned long long)row->size + tabs * 8 + nonprint * 9 + 1;
if (allocsize > __UINT32_MAX__)
{
printf("Some line of the edited file is too long for Txt42\n");
exit(1);
}
row->render = malloc(row->size + tabs * 8 + nonprint * 9 + 1);
idx = 0;
for (j = 0; j < row->size; j++)
{
if (row->chars[j] == TAB)
{
row->render[idx++] = ' ';
while ((idx + 1) % 8 != 0)
row->render[idx++] = ' ';
}
else
{
row->render[idx++] = row->chars[j];
}
}
row->rsize = idx;
row->render[idx] = '\0';
/* Update the syntax highlighting attributes of the row. */
editorUpdateSyntax(row);
}
/* Insert a row at the specified position, shifting the other rows on the bottom
* if required. */
void editorInsertRow(int at, char *s, size_t len)
{
if (at > E.numrows)
return;
E.row = realloc(E.row, sizeof(erow) * (E.numrows + 1));
if (at != E.numrows)
{
memmove(E.row + at + 1, E.row + at, sizeof(E.row[0]) * (E.numrows - at));
for (int j = at + 1; j <= E.numrows; j++)
E.row[j].idx++;
}
E.row[at].size = len;
E.row[at].chars = malloc(len + 1);
memcpy(E.row[at].chars, s, len + 1);
E.row[at].hl = NULL;
E.row[at].hl_oc = 0;
E.row[at].render = NULL;
E.row[at].rsize = 0;
E.row[at].idx = at;
editorUpdateRow(E.row + at);
E.numrows++;
E.dirty++;
}
/* Free row's heap allocated stuff. */
void editorFreeRow(erow *row)
{
free(row->render);
free(row->chars);
free(row->hl);
}
/* Remove the row at the specified position, shifting the remainign on the
* top. */
void editorDelRow(int at)
{
erow *row;
if (at >= E.numrows)
return;
row = E.row + at;
editorFreeRow(row);
memmove(E.row + at, E.row + at + 1, sizeof(E.row[0]) * (E.numrows - at - 1));
for (int j = at; j < E.numrows - 1; j++)
E.row[j].idx++;
E.numrows--;
E.dirty++;
}
/* Turn the editor rows into a single heap-allocated string.
* Returns the pointer to the heap-allocated string and populate the
* integer pointed by 'buflen' with the size of the string, escluding
* the final nulterm. */
char *editorRowsToString(int *buflen)
{
char *buf = NULL, *p;
int totlen = 0;
int j;
/* Compute count of bytes */
for (j = 0; j < E.numrows; j++)
totlen += E.row[j].size + 1; /* +1 is for "\n" at end of every row */
*buflen = totlen;
totlen++; /* Also make space for nulterm */
p = buf = malloc(totlen);
for (j = 0; j < E.numrows; j++)
{
memcpy(p, E.row[j].chars, E.row[j].size);
p += E.row[j].size;
*p = '\n';
p++;
}
*p = '\0';
return buf;
}
/* Insert a character at the specified position in a row, moving the remaining
* chars on the right if needed. */
void editorRowInsertChar(erow *row, int at, int c)
{
if (at > row->size)
{
/* Pad the string with spaces if the insert location is outside the
* current length by more than a single character. */
int padlen = at - row->size;
/* In the next line +2 means: new char and null term. */
row->chars = realloc(row->chars, row->size + padlen + 2);
memset(row->chars + row->size, ' ', padlen);
row->chars[row->size + padlen + 1] = '\0';
row->size += padlen + 1;
}
else
{
/* If we are in the middle of the string just make space for 1 new
* char plus the (already existing) null term. */
row->chars = realloc(row->chars, row->size + 2);
memmove(row->chars + at + 1, row->chars + at, row->size - at + 1);
row->size++;
}
row->chars[at] = c;
editorUpdateRow(row);
E.dirty++;
}
/* Append the string 's' at the end of a row */
void editorRowAppendString(erow *row, char *s, size_t len)
{
row->chars = realloc(row->chars, row->size + len + 1);
memcpy(row->chars + row->size, s, len);
row->size += len;
row->chars[row->size] = '\0';
editorUpdateRow(row);
E.dirty++;
}
/* Delete the character at offset 'at' from the specified row. */
void editorRowDelChar(erow *row, int at)
{
if (row->size <= at)
return;
memmove(row->chars + at, row->chars + at + 1, row->size - at);
editorUpdateRow(row);
row->size--;
E.dirty++;
}
/* Insert the specified char at the current prompt position. */
void editorInsertChar(int c)
{
int filerow = E.rowoff + E.cy;
int filecol = E.coloff + E.cx;
erow *row = (filerow >= E.numrows) ? NULL : &E.row[filerow];
/* If the row where the cursor is currently located does not exist in our
* logical representaion of the file, add enough empty rows as needed. */
if (!row)
{
while (E.numrows <= filerow)
editorInsertRow(E.numrows, "", 0);
}
row = &E.row[filerow];
editorRowInsertChar(row, filecol, c);
if (E.cx == E.screencols - 1)
E.coloff++;
else
E.cx++;
E.dirty++;
}
/* Inserting a newline is slightly complex as we have to handle inserting a
* newline in the middle of a line, splitting the line as needed. */
void editorInsertNewline(void)
{
int filerow = E.rowoff + E.cy;
int filecol = E.coloff + E.cx;
erow *row = (filerow >= E.numrows) ? NULL : &E.row[filerow];
if (!row)
{
if (filerow == E.numrows)
{
editorInsertRow(filerow, "", 0);
goto fixcursor;
}
return;
}
/* If the cursor is over the current line size, we want to conceptually
* think it's just over the last character. */
if (filecol >= row->size)
filecol = row->size;
if (filecol == 0)
{
editorInsertRow(filerow, "", 0);
}
else
{
/* We are in the middle of a line. Split it between two rows. */
editorInsertRow(filerow + 1, row->chars + filecol, row->size - filecol);
row = &E.row[filerow];
row->chars[filecol] = '\0';
row->size = filecol;
editorUpdateRow(row);
}
fixcursor:
if (E.cy == E.screenrows - 1)
{
E.rowoff++;
}
else
{
E.cy++;
}
E.cx = 0;
E.coloff = 0;
}
/* Delete the char at the current prompt position. */
void editorDelChar()
{
int filerow = E.rowoff + E.cy;
int filecol = E.coloff + E.cx;
erow *row = (filerow >= E.numrows) ? NULL : &E.row[filerow];
if (!row || (filecol == 0 && filerow == 0))
return;
if (filecol == 0)
{
/* Handle the case of column 0, we need to move the current line
* on the right of the previous one. */
filecol = E.row[filerow - 1].size;
editorRowAppendString(&E.row[filerow - 1], row->chars, row->size);
editorDelRow(filerow);
row = NULL;
if (E.cy == 0)
E.rowoff--;
else
E.cy--;
E.cx = filecol;
if (E.cx >= E.screencols)
{
int shift = (E.screencols - E.cx) + 1;
E.cx -= shift;
E.coloff += shift;
}
}
else
{
editorRowDelChar(row, filecol - 1);
if (E.cx == 0 && E.coloff)
E.coloff--;
else
E.cx--;
}
if (row)
editorUpdateRow(row);
E.dirty++;
}
/* Load the specified program in the editor memory and returns 0 on success
* or 1 on error. */
int editorOpen(char *filename)
{
FILE *fp;
E.dirty = 0;
free(E.filename);
size_t fnlen = strlen(filename) + 1;
E.filename = malloc(fnlen);
memcpy(E.filename, filename, fnlen);
fp = fopen(filename, "r");
if (!fp)
{
if (errno != ENOENT)
{
perror("Opening file");
exit(1);
}
return 1;
}
char *line = NULL;
size_t linecap = 0;
ssize_t linelen;
while ((linelen = getline(&line, &linecap, fp)) != -1)
{
if (linelen && (line[linelen - 1] == '\n' || line[linelen - 1] == '\r'))
line[--linelen] = '\0';
editorInsertRow(E.numrows, line, linelen);
}
free(line);
fclose(fp);
E.dirty = 0;
return 0;
}
/* Save the current file on disk. Return 0 on success, 1 on error. */
int editorSave(void)
{
int len;
char *buf = editorRowsToString(&len);
int fd = open(E.filename, O_RDWR | O_CREAT, 0644);
if (fd == -1)
goto writeerr;
/* Use truncate + a single write(2) call in order to make saving
* a bit safer, under the limits of what we can do in a small editor. */
if (ftruncate(fd, len) == -1)
goto writeerr;
if (write(fd, buf, len) != len)
goto writeerr;
close(fd);
free(buf);
E.dirty = 0;
editorSetStatusMessage("%d bytes written on disk", len);
return 0;
writeerr:
free(buf);
if (fd != -1)
close(fd);
editorSetStatusMessage("Can't save! I/O error: %s", strerror(errno));
return 1;
}
struct abuf
{
char *b;
int len;
};
#define ABUF_INIT \
{ \
NULL, 0 \
}
void abAppend(struct abuf *ab, const char *s, int len)
{
char *new = realloc(ab->b, ab->len + len);
if (new == NULL)
return;
memcpy(new + ab->len, s, len);
ab->b = new;
ab->len += len;
}
void abFree(struct abuf *ab)
{
free(ab->b);
}
/* This function writes the whole screen using VT100 escape characters
* starting from the logical state of the editor in the global state 'E'. */
void editorRefreshScreen(void)
{
int y;
erow *r;
char buf[32];
struct abuf ab = ABUF_INIT;
abAppend(&ab, "\x1b[?25l", 6); /* Hide cursor. */
abAppend(&ab, "\x1b[H", 3); /* Go home. */
for (y = 0; y < E.screenrows; y++)
{
int filerow = E.rowoff + y;
if (filerow >= E.numrows)
{
if (E.numrows == 0 && y == E.screenrows / 3)
{
char welcome[80];
int welcomelen = snprintf(welcome, sizeof(welcome),
"Txt42 editor -- verison %s\x1b[0K\r\n", TXT42_VERSION);