哈希空间
实现一个简单文本编辑器？
直接可以参考的例子 redis 作者写的 kilo
A text editor in less than 1000 LOC with syntax highlight and search.
即使用一千行代码实现的编辑器包含语法高亮和搜索。
https://github.com/antirez/kilo
代码简单、干练 非常值得学习参考！
一个纯C语言文件实现，没有其它依赖库，比如常见的 curses 都没有用到。直接读取按键信息进行控制编辑。
CTRL-S: 保存
CTRL-Q: 退出
CTRL-F: 搜索 (ESC 退出, 方向键导航)
这是个非常有意思的实现。
因为仅1000行左右，这里贴出完整的源代码，如果你使用的是 Linux 或 macOS，可以使用如下命令直接编译：gcc kilo.c -o kilo
./kilo a.c 就可以编辑文件
有行号的支持，但是仅支持ASCII字符的编辑支持。如果要支持其它语言的良好支持，还有很多工作要做。
/* Kilo -- A very simple editor in less than 1-kilo lines of code (as counted
* by "cloc"). Does not depend on libcurses, directly emits VT100
* escapes on the terminal.
*
* -----------------------------------------------------------------------
*
* Copyright (C) 2016 Salvatore Sanfilippo <antirez at gmail dot com>
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#define KILO_VERSION "0.0.1"
#ifdef __linux__
#define _POSIX_C_SOURCE 200809L
#endif
#include <termios.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdint.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 /* Single line comment. */
#define HL_MLCOMMENT 3 /* Multi-line comment. */
#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;
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, ...);
/* =========================== Syntax highlights DB =========================
*
* In order to add a new syntax, define two arrays with a list of file name
* matches and keywords. The file name matches are used in order to match
* a given syntax with a given file name: if a match pattern starts with a
* dot, it is matched as the last past of the filename, for example ".c".
* Otherwise the pattern is just searched inside the filenme, like "Makefile").
*
* The list of keywords to highlight is just a list of words, however if they
* a trailing '|' character is added at the end, they are highlighted in
* a different color, so that you can have two different sets of keywords.
*
* Finally add a stanza in the HLDB global variable with two two arrays
* of strings, and a set of flags in order to enable highlighting of
* comments and numbers.
*
* The characters for single and multi line comments must be exactly two
* and must be provided as well (see the C language example).
*
* There is no support to highlight patterns currently. */
/* 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 kilo\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;
}
/* ============================= Terminal update ============================ */
/* We define a very simple "append buffer" structure, that is an heap
* allocated string where we can append to. This is useful in order to
* write all the escape sequences in a buffer and flush them to the standard
* output in a single call, to avoid flickering effects. */
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),
"Kilo editor -- verison %s\x1b[0K\r\n", KILO_VERSION);
int padding = (E.screencols-welcomelen)/2;
if (padding) {
abAppend(&ab,"~",1);
padding--;
}
while(padding--) abAppend(&ab," ",1);
abAppend(&ab,welcome,welcomelen);
} else {
abAppend(&ab,"~\x1b[0K\r\n",7);
}
continue;
}
r = &E.row[filerow];
int len = r->rsize - E.coloff;
int current_color = -1;
if (len > 0) {
if (len > E.screencols) len = E.screencols;
char *c = r->render+E.coloff;
unsigned char *hl = r->hl+E.coloff;
int j;
for (j = 0; j < len; j++) {
if (hl[j] == HL_NONPRINT) {
char sym;
abAppend(&ab,"\x1b[7m",4);
if (c[j] <= 26)
sym = '@'+c[j];
else
sym = '?';
abAppend(&ab,&sym,1);
abAppend(&ab,"\x1b[0m",4);
} else if (hl[j] == HL_NORMAL) {
if (current_color != -1) {
abAppend(&ab,"\x1b[39m",5);
current_color = -1;
}
abAppend(&ab,c+j,1);
} else {
int color = editorSyntaxToColor(hl[j]);
if (color != current_color) {
char buf[16];
int clen = snprintf(buf,sizeof(buf),"\x1b[%dm",color);
current_color = color;
abAppend(&ab,buf,clen);
}
abAppend(&ab,c+j,1);
}
}
}
abAppend(&ab,"\x1b[39m",5);
abAppend(&ab,"\x1b[0K",4);
abAppend(&ab,"\r\n",2);
}
/* Create a two rows status. First row: */
abAppend(&ab,"\x1b[0K",4);
abAppend(&ab,"\x1b[7m",4);
char status[80], rstatus[80];
int len = snprintf(status, sizeof(status), "%.20s - %d lines %s",
E.filename, E.numrows, E.dirty ? "(modified)" : "");
int rlen = snprintf(rstatus, sizeof(rstatus),
"%d/%d",E.rowoff+E.cy+1,E.numrows);
if (len > E.screencols) len = E.screencols;
abAppend(&ab,status,len);
while(len < E.screencols) {
if (E.screencols - len == rlen) {
abAppend(&ab,rstatus,rlen);
break;
} else {
abAppend(&ab," ",1);
len++;
}
}
abAppend(&ab,"\x1b[0m\r\n",6);
/* Second row depends on E.statusmsg and the status message update time. */
abAppend(&ab,"\x1b[0K",4);
int msglen = strlen(E.statusmsg);
if (msglen && time(NULL)-E.statusmsg_time < 5)
abAppend(&ab,E.statusmsg,msglen <= E.screencols ? msglen : E.screencols);
/* Put cursor at its current position. Note that the horizontal position
* at which the cursor is displayed may be different compared to 'E.cx'
* because of TABs. */
int j;
int cx = 1;
int filerow = E.rowoff+E.cy;
erow *row = (filerow >= E.numrows) ? NULL : &E.row[filerow];
if (row) {
for (j = E.coloff; j < (E.cx+E.coloff); j++) {
if (j < row->size && row->chars[j] == TAB) cx += 7-((cx)%8);
cx++;
}
}
snprintf(buf,sizeof(buf),"\x1b[%d;%dH",E.cy+1,cx);
abAppend(&ab,buf,strlen(buf));
abAppend(&ab,"\x1b[?25h",6); /* Show cursor. */
write(STDOUT_FILENO,ab.b,ab.len);
abFree(&ab);
}
/* Set an editor status message for the second line of the status, at the
* end of the screen. */
void editorSetStatusMessage(const char *fmt, ...) {
va_list ap;
va_start(ap,fmt);
vsnprintf(E.statusmsg,sizeof(E.statusmsg),fmt,ap);
va_end(ap);
E.statusmsg_time = time(NULL);
}
/* =============================== Find mode ================================ */
#define KILO_QUERY_LEN 256
void editorFind(int fd) {
char query[KILO_QUERY_LEN+1] = {0};
int qlen = 0;
int last_match = -1; /* Last line where a match was found. -1 for none. */
int find_next = 0; /* if 1 search next, if -1 search prev. */
int saved_hl_line = -1; /* No saved HL */
char *saved_hl = NULL;
#define FIND_RESTORE_HL do { \
if (saved_hl) { \
memcpy(E.row[saved_hl_line].hl,saved_hl, E.row[saved_hl_line].rsize); \
free(saved_hl); \
saved_hl = NULL; \
} \
} while (0)
/* Save the cursor position in order to restore it later. */
int saved_cx = E.cx, saved_cy = E.cy;
int saved_coloff = E.coloff, saved_rowoff = E.rowoff;
while(1) {
editorSetStatusMessage(
"Search: %s (Use ESC/Arrows/Enter)", query);
editorRefreshScreen();
int c = editorReadKey(fd);
if (c == DEL_KEY || c == CTRL_H || c == BACKSPACE) {
if (qlen != 0) query[--qlen] = '\0';
last_match = -1;
} else if (c == ESC || c == ENTER) {
if (c == ESC) {
E.cx = saved_cx; E.cy = saved_cy;
E.coloff = saved_coloff; E.rowoff = saved_rowoff;
}
FIND_RESTORE_HL;
editorSetStatusMessage("");
return;
} else if (c == ARROW_RIGHT || c == ARROW_DOWN) {
find_next = 1;
} else if (c == ARROW_LEFT || c == ARROW_UP) {
find_next = -1;
} else if (isprint(c)) {
if (qlen < KILO_QUERY_LEN) {
query[qlen++] = c;
query[qlen] = '\0';
last_match = -1;
}
}
/* Search occurrence. */
if (last_match == -1) find_next = 1;
if (find_next) {
char *match = NULL;
int match_offset = 0;
int i, current = last_match;
for (i = 0; i < E.numrows; i++) {
current += find_next;
if (current == -1) current = E.numrows-1;
else if (current == E.numrows) current = 0;
match = strstr(E.row[current].render,query);
if (match) {
match_offset = match-E.row[current].render;
break;
}
}
find_next = 0;
/* Highlight */
FIND_RESTORE_HL;
if (match) {
erow *row = &E.row[current];
last_match = current;
if (row->hl) {
saved_hl_line = current;
saved_hl = malloc(row->rsize);
memcpy(saved_hl,row->hl,row->rsize);
memset(row->hl+match_offset,HL_MATCH,qlen);
}
E.cy = 0;
E.cx = match_offset;
E.rowoff = current;
E.coloff = 0;
/* Scroll horizontally as needed. */
if (E.cx > E.screencols) {
int diff = E.cx - E.screencols;
E.cx -= diff;
E.coloff += diff;
}
}
}
}
}
/* ========================= Editor events handling ======================== */
/* Handle cursor position change because arrow keys were pressed. */
void editorMoveCursor(int key) {
int filerow = E.rowoff+E.cy;
int filecol = E.coloff+E.cx;
int rowlen;
erow *row = (filerow >= E.numrows) ? NULL : &E.row[filerow];
switch(key) {
case ARROW_LEFT:
if (E.cx == 0) {
if (E.coloff) {
E.coloff--;
} else {
if (filerow > 0) {
E.cy--;
E.cx = E.row[filerow-1].size;
if (E.cx > E.screencols-1) {
E.coloff = E.cx-E.screencols+1;
E.cx = E.screencols-1;
}
}
}
} else {
E.cx -= 1;
}
break;
case ARROW_RIGHT:
if (row && filecol < row->size) {
if (E.cx == E.screencols-1) {
E.coloff++;
} else {
E.cx += 1;
}
} else if (row && filecol == row->size) {
E.cx = 0;
E.coloff = 0;
if (E.cy == E.screenrows-1) {
E.rowoff++;
} else {
E.cy += 1;
}
}
break;
case ARROW_UP:
if (E.cy == 0) {
if (E.rowoff) E.rowoff--;
} else {
E.cy -= 1;
}
break;
case ARROW_DOWN:
if (filerow < E.numrows) {
if (E.cy == E.screenrows-1) {
E.rowoff++;
} else {
E.cy += 1;
}
}
break;
}
/* Fix cx if the current line has not enough chars. */
filerow = E.rowoff+E.cy;
filecol = E.coloff+E.cx;
row = (filerow >= E.numrows) ? NULL : &E.row[filerow];
rowlen = row ? row->size : 0;
if (filecol > rowlen) {
E.cx -= filecol-rowlen;
if (E.cx < 0) {
E.coloff += E.cx;
E.cx = 0;
}
}
}
/* Process events arriving from the standard input, which is, the user
* is typing stuff on the terminal. */
#define KILO_QUIT_TIMES 3
void editorProcessKeypress(int fd) {
/* When the file is modified, requires Ctrl-q to be pressed N times
* before actually quitting. */
static int quit_times = KILO_QUIT_TIMES;
int c = editorReadKey(fd);
switch(c) {
case ENTER: /* Enter */
editorInsertNewline();
break;
case CTRL_C: /* Ctrl-c */
/* We ignore ctrl-c, it can't be so simple to lose the changes
* to the edited file. */
break;
case CTRL_Q: /* Ctrl-q */
/* Quit if the file was already saved. */
if (E.dirty && quit_times) {
editorSetStatusMessage("WARNING!!! File has unsaved changes. "
"Press Ctrl-Q %d more times to quit.", quit_times);
quit_times--;
return;
}
exit(0);
break;
case CTRL_S: /* Ctrl-s */
editorSave();
break;
case CTRL_F:
editorFind(fd);
break;
case BACKSPACE: /* Backspace */
case CTRL_H: /* Ctrl-h */
case DEL_KEY:
editorDelChar();
break;
case PAGE_UP:
case PAGE_DOWN:
if (c == PAGE_UP && E.cy != 0)
E.cy = 0;
else if (c == PAGE_DOWN && E.cy != E.screenrows-1)
E.cy = E.screenrows-1;
{
int times = E.screenrows;
while(times--)
editorMoveCursor(c == PAGE_UP ? ARROW_UP:
ARROW_DOWN);
}
break;
case ARROW_UP:
case ARROW_DOWN:
case ARROW_LEFT:
case ARROW_RIGHT:
editorMoveCursor(c);
break;
case CTRL_L: /* ctrl+l, clear screen */
/* Just refresht the line as side effect. */
break;
case ESC:
/* Nothing to do for ESC in this mode. */
break;
default:
editorInsertChar(c);
break;
}
quit_times = KILO_QUIT_TIMES; /* Reset it to the original value. */
}
int editorFileWasModified(void) {
return E.dirty;
}
void updateWindowSize(void) {
if (getWindowSize(STDIN_FILENO,STDOUT_FILENO,
&E.screenrows,&E.screencols) == -1) {
perror("Unable to query the screen for size (columns / rows)");
exit(1);
}
E.screenrows -= 2; /* Get room for status bar. */
}
void handleSigWinCh(int unused __attribute__((unused))) {
updateWindowSize();
if (E.cy > E.screenrows) E.cy = E.screenrows - 1;
if (E.cx > E.screencols) E.cx = E.screencols - 1;
editorRefreshScreen();
}
void initEditor(void) {
E.cx = 0;
E.cy = 0;
E.rowoff = 0;
E.coloff = 0;
E.numrows = 0;
E.row = NULL;
E.dirty = 0;
E.filename = NULL;
E.syntax = NULL;
updateWindowSize();
signal(SIGWINCH, handleSigWinCh);
}
int main(int argc, char **argv) {
if (argc != 2) {
fprintf(stderr,"Usage: kilo <filename>\n");
exit(1);
}
initEditor();
editorSelectSyntaxHighlight(argv[1]);
editorOpen(argv[1]);
enableRawMode(STDIN_FILENO);
editorSetStatusMessage(
"HELP: Ctrl-S = save | Ctrl-Q = quit | Ctrl-F = find");
while(1) {
editorRefreshScreen();
editorProcessKeypress(STDIN_FILENO);
}
return 0;
}
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