kilo TextEditor-4

语法高亮显示

数字的颜色

void editorDrawRows(struct abuf *ab) {
    int y;
    for (y = 0; y < E.screenrows; y++) {
        int filerow = y + E.rowoff;
        if (filerow >= E.numrows) {
            if (E.numrows == 0 && y == E.screenrows / 3) {
                char welcome[80];
                int welcomelen = snprintf(welcome, sizeof(welcome),
                                          "Kilo editor -- version %s", KILO_VERSION);
                if (welcomelen > E.screencols) welcomelen = E.screencols;
                int padding = (E.screencols - welcomelen) / 2;
                if (padding) {
                    abAppend(ab, "~", 1);
                    padding--;
                }
                while (padding--) abAppend(ab, " ", 1);
                abAppend(ab, welcome, welcomelen);
            } else {
                abAppend(ab, "~", 1);
            }
        } else {
            int len = E.row[filerow].rsize - E.coloff;
            if (len < 0) len = 0;
            if (len > E.screencols) len = E.screencols;
            
            char *c = &E.row[filerow].render[E.coloff];
            int j;
            for (j = 0; j < len; j++) {
                if (isdigit(c[j])) {
                    //如果是数字就先调整文本颜色再写入数字，之后调整回来
                    abAppend(ab, "\x1b[31m", 5);
                    abAppend(ab, &c[j], 1);
                    abAppend(ab, "\x1b[39m", 5);
                } else {
                    abAppend(ab, &c[j], 1);
                }
            }
        }
        abAppend(ab, "\x1b[K", 3);
        abAppend(ab, "\r\n", 2);
    }
}

重构语法高亮显示

typedef struct erow {
    int size;
    int rsize;
    char *chars;
    char *render;
    unsigned char *hl;//render中字符的高亮标记，每个元素对应同样下标的render中的字符
} erow;

void editorInsertRow(int at, char *s, size_t len) {
    if (at < 0 || at > E.numrows) return;
    E.row = realloc(E.row, sizeof(erow) * (E.numrows + 1));
    memmove(&E.row[at + 1], &E.row[at], sizeof(erow) * (E.numrows - at));
    E.row[at].size = len;
    E.row[at].chars = malloc(len + 1);
    memcpy(E.row[at].chars, s, len);
    E.row[at].chars[len] = '\0';
    E.row[at].rsize = 0;
    E.row[at].render = NULL;
    E.row[at].hl = NULL;
    editorUpdateRow(&E.row[at]);
    E.numrows++;
    E.dirty++;
}

void editorFreeRow(erow *row) {
    free(row->render);
    free(row->chars);
    free(row->hl);
}

enum editorHighlight {
    HL_NORMAL = 0,
    HL_NUMBER//专注于高亮数字
};

填充hl中render对应的字符的高亮标记

void editorUpdateSyntax(erow *row) {
    row->hl = realloc(row->hl, row->rsize);
    memset(row->hl, HL_NORMAL, row->rsize);
    int i;
    for (i = 0; i < row->rsize; i++) {
        if (isdigit(row->render[i])) {
            row->hl[i] = HL_NUMBER;
        }
    }
}

void editorUpdateRow(erow *row) {
    int tabs = 0;
    int j;
    for (j = 0; j < row->size; j++)
        if (row->chars[j] == '\t') tabs++;
    free(row->render);
    row->render = malloc(row->size + tabs*(KILO_TAB_STOP - 1) + 1);
    int idx = 0;
    for (j = 0; j < row->size; j++) {
        if (row->chars[j] == '\t') {
            row->render[idx++] = ' ';
            while (idx % KILO_TAB_STOP != 0) row->render[idx++] = ' ';
        } else {
            row->render[idx++] = row->chars[j];
        }
    }
    row->render[idx] = '\0';
    row->rsize = idx;
    editorUpdateSyntax(row);
}

将枚举类映射到对应ANSI颜色代码

int editorSyntaxToColor(int hl) {
    switch (hl) {
        case HL_NUMBER: return 31;
        default: return 37;
    }
}

最终通过hl获得高亮信息，然后显示

void editorDrawRows(struct abuf *ab) {
    int y;
    for (y = 0; y < E.screenrows; y++) {
        int filerow = y + E.rowoff;
        if (filerow >= E.numrows) {
            if (E.numrows == 0 && y == E.screenrows / 3) {
                char welcome[80];
                int welcomelen = snprintf(welcome, sizeof(welcome),
                                          "Kilo editor -- version %s", KILO_VERSION);
                if (welcomelen > E.screencols) welcomelen = E.screencols;
                int padding = (E.screencols - welcomelen) / 2;
                if (padding) {
                    abAppend(ab, "~", 1);
                    padding--;
                }
                while (padding--) abAppend(ab, " ", 1);
                abAppend(ab, welcome, welcomelen);
            } else {
                abAppend(ab, "~", 1);
            }
        } else {
            int len = E.row[filerow].rsize - E.coloff;
            if (len < 0) len = 0;
            if (len > E.screencols) len = E.screencols;
            char *c = &E.row[filerow].render[E.coloff];
            //获取高亮信息
            unsigned char *hl = &E.row[filerow].hl[E.coloff];
            int current_color = -1;//通过记录过去的颜色来省去重复设置颜色
            int j;
            for (j = 0; j < len; j++) {
                if (hl[j] == HL_NORMAL) {
                    if (current_color != -1) {
                        abAppend(ab, "\x1b[39m", 5);
                        current_color = -1;
                    }
                    abAppend(ab, &c[j], 1);
                } else {
                    //转换为颜色码
                    int color = editorSyntaxToColor(hl[j]);
                    if (color != current_color) {
                        current_color = color;
                        char buf[16];
                        int clen = snprintf(buf, sizeof(buf), "\x1b[%dm", color);
                        abAppend(ab, buf, clen);
                    }
                    abAppend(ab, &c[j], 1);
                }
            }
            abAppend(ab, "\x1b[39m", 5);
        }
        abAppend(ab, "\x1b[K", 3);
        abAppend(ab, "\r\n", 2);
    }
}

搜索结果添加颜色

enum editorHighlight {
    HL_NORMAL = 0,
    HL_NUMBER,
    HL_MATCH
};

int editorSyntaxToColor(int hl) {
    switch (hl) {
        case HL_NUMBER: return 31;
        case HL_MATCH: return 34;
        default: return 37;
    }
}

void editorFindCallback(char *query, int key) {
    static int last_match = -1;
    static int direction = 1;
    if (key == '\r' || key == '\x1b') {
        last_match = -1;
        direction = 1;
        return;
    } else if (key == ARROW_RIGHT || key == ARROW_DOWN) {
        direction = 1;
    } else if (key == ARROW_LEFT || key == ARROW_UP) {
        direction = -1;
    } else {
        last_match = -1;
        direction = 1;
    }
    if (last_match == -1) direction = 1;
    int current = last_match;
    int i;
    for (i = 0; i < E.numrows; i++) {
        current += direction;
        if (current == -1) current = E.numrows - 1;
        else if (current == E.numrows) current = 0;
        erow *row = &E.row[current];
        char *match = strstr(row->render, query);
        if (match) {
            last_match = current;
            E.cy = current;
            E.cx = editorRowRxToCx(row, match - row->render);
            E.rowoff = E.numrows;
            
            //填充对应字符的高亮信息
            memset(&row->hl[match - row->render], HL_MATCH, strlen(query));
            break;
        }
    }
}

搜索后恢复高亮

void editorFindCallback(char *query, int key) {
    static int last_match = -1;
    static int direction = 1;
    
    static int saved_hl_line;
    static char *saved_hl = NULL;
    if (saved_hl) {
        //如果有保存着的（上个查询的）高亮信息，就把对应的行恢复
        memcpy(E.row[saved_hl_line].hl, saved_hl, E.row[saved_hl_line].rsize);
        free(saved_hl);
        saved_hl = NULL;
    }
    
    if (key == '\r' || key == '\x1b') {
        last_match = -1;
        direction = 1;
        return;
    } else if (key == ARROW_RIGHT || key == ARROW_DOWN) {
        direction = 1;
    } else if (key == ARROW_LEFT || key == ARROW_UP) {
        direction = -1;
    } else {
        last_match = -1;
        direction = 1;
    }
    if (last_match == -1) direction = 1;
    int current = last_match;
    int i;
    for (i = 0; i < E.numrows; i++) {
        current += direction;
        if (current == -1) current = E.numrows - 1;
        else if (current == E.numrows) current = 0;
        erow *row = &E.row[current];
        char *match = strstr(row->render, query);
        if (match) {
            last_match = current;
            E.cy = current;
            E.cx = editorRowRxToCx(row, match - row->render);
            E.rowoff = E.numrows;
            
            //高亮前保存高亮信息
            saved_hl_line = current;
            saved_hl = malloc(row->rsize);
            memcpy(saved_hl, row->hl, row->rsize);
            memset(&row->hl[match - row->render], HL_MATCH, strlen(query));
            break;
        }
    }
}

多彩的数字

void editorUpdateSyntax(erow *row) {
    row->hl = realloc(row->hl, row->rsize);
    memset(row->hl, HL_NORMAL, row->rsize);
    int i = 0;
    while (i < row->rsize) {
        char c = row->render[i];
        if (isdigit(c)) {
            row->hl[i] = HL_NUMBER;
        }
        i++;
    }
}

判断间隔符

int is_separator(int c) {
    return isspace(c) || c == '\0' || strchr(",.()+-/*=~%<>[];", c) != NULL;
}

void editorUpdateSyntax(erow *row) {
    row->hl = realloc(row->hl, row->rsize);
    memset(row->hl, HL_NORMAL, row->rsize);
    int prev_sep = 1;
    int i = 0;
    while (i < row->rsize) {
        char c = row->render[i];
        unsigned char prev_hl = (i > 0) ? row->hl[i - 1] : HL_NORMAL;
        if (isdigit(c) && (prev_sep || prev_hl == HL_NUMBER)) {
            row->hl[i] = HL_NUMBER;
            i++;
            prev_sep = 0;
            continue;
        }
        //判断前一个字符是否是间隔符
        prev_sep = is_separator(c);
        i++;
    }
}

支持高亮小数点

void editorUpdateSyntax(erow *row) {
    row->hl = realloc(row->hl, row->rsize);
    memset(row->hl, HL_NORMAL, row->rsize);
    int prev_sep = 1;
    int i = 0;
    while (i < row->rsize) {
        char c = row->render[i];
        unsigned char prev_hl = (i > 0) ? row->hl[i - 1] : HL_NORMAL;
        //兼容小数点
        if ((isdigit(c) && (prev_sep || prev_hl == HL_NUMBER)) ||
            (c == '.' && prev_hl == HL_NUMBER)) {
            
            row->hl[i] = HL_NUMBER;
            i++;
            prev_sep = 0;
            continue;
        }
        prev_sep = is_separator(c);
        i++;
    }
}

检测文件类型

#define HL_HIGHLIGHT_NUMBERS (1<<0)

struct editorSyntax {
    char *filetype;
    char **filematch;
    int flags;
};

char *C_HL_extensions[] = { ".c", ".h", ".cpp", NULL };
struct editorSyntax HLDB[] = {
    {
        "c",
        C_HL_extensions,
        HL_HIGHLIGHT_NUMBERS
    },
};
#define HLDB_ENTRIES (sizeof(HLDB) / sizeof(HLDB[0]))

struct editorConfig {
    int cx, cy;
    int rx;
    int rowoff;
    int coloff;
    int screenrows;
    int screencols;
    int numrows;
    erow *row;
    int dirty;
    char *filename;
    char statusmsg[80];
    time_t statusmsg_time;
    struct editorSyntax *syntax;//
    struct termios orig_termios;
};

void initEditor() {
    E.cx = 0;
    E.cy = 0;
    E.rx = 0;
    E.rowoff = 0;
    E.coloff = 0;
    E.numrows = 0;
    E.row = NULL;
    E.dirty = 0;
    E.filename = NULL;
    E.statusmsg[0] = '\0';
    E.statusmsg_time = 0;
    E.syntax = NULL;
    if (getWindowSize(&E.screenrows, &E.screencols) == -1) die("getWindowSize");
    E.screenrows -= 2;
}

在状态栏中显示文件类型

void editorDrawStatusBar(struct abuf *ab) {
    abAppend(ab, "\x1b[7m", 4);
    char status[80], rstatus[80];
    //文件名+总行数
    int len = snprintf(status, sizeof(status), "%.20s - %d lines %s",
                       E.filename ? E.filename : "[No Name]", E.numrows,
                       E.dirty ? "(modified)" : "");
    //文件类型+当前行数/总行数
    int rlen = snprintf(rstatus, sizeof(rstatus), "%s | %d/%d",
                        E.syntax ? E.syntax->filetype : "no ft", 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[m", 3);
    abAppend(ab, "\r\n", 2);
}

应用文件类型检测

void editorUpdateSyntax(erow *row) {
    row->hl = realloc(row->hl, row->rsize);
    memset(row->hl, HL_NORMAL, row->rsize);
    //未知文件类型，不设置高亮
    if (E.syntax == NULL) return;
    int prev_sep = 1;
    int i = 0;
    while (i < row->rsize) {
        char c = row->render[i];
        unsigned char prev_hl = (i > 0) ? row->hl[i - 1] : HL_NORMAL;
        //
        if (E.syntax->flags & HL_HIGHLIGHT_NUMBERS) {
            if ((isdigit(c) && (prev_sep || prev_hl == HL_NUMBER)) ||
                (c == '.' && prev_hl == HL_NUMBER)) {
                row->hl[i] = HL_NUMBER;
                i++;
                prev_sep = 0;
                continue;
            }
        }
        prev_sep = is_separator(c);
        i++;
    }
}

void editorSelectSyntaxHighlight() {
    E.syntax = NULL;
    if (E.filename == NULL) return;
    char *ext = strrchr(E.filename, '.');
    for (unsigned int j = 0; j < HLDB_ENTRIES; j++) {
        struct editorSyntax *s = &HLDB[j];
        unsigned int i = 0;
        while (s->filematch[i]) {
            int is_ext = (s->filematch[i][0] == '.');
            if ((is_ext && ext && !strcmp(ext, s->filematch[i])) ||
                (!is_ext && strstr(E.filename, s->filematch[i]))) {
                E.syntax = s;
                int filerow;
                for (filerow = 0; filerow < E.numrows; filerow++) {
                    //从头开始更新文件高亮
                    editorUpdateSyntax(&E.row[filerow]);
                }
                return;
            }
            i++;
        }
    }
}

调用检测文件类型函数

void editorOpen(char *filename) {
    free(E.filename);
    E.filename = strdup(filename);
    //解析文件类型，设置高亮信息
    editorSelectSyntaxHighlight();
    
    FILE *fp = fopen(filename, "r");
    if (!fp) die("fopen");
    char *line = NULL;
    size_t linecap = 0;
    ssize_t linelen;
    while ((linelen = getline(&line, &linecap, fp)) != -1) {
        while (linelen > 0 && (line[linelen - 1] == '\n' ||
                               line[linelen - 1] == '\r'))
            linelen--;
        editorInsertRow(E.numrows, line, linelen);
    }
    free(line);
    fclose(fp);
    E.dirty = 0;
}
void editorSave() {
    if (E.filename == NULL) {
        E.filename = editorPrompt("Save as: %s (ESC to cancel)", NULL);
        if (E.filename == NULL) {
            editorSetStatusMessage("Save aborted");
            return;
        }
        //解析文件类型，设置高亮信息
        editorSelectSyntaxHighlight();
        
    }
    int len;
    char *buf = editorRowsToString(&len);
    int fd = open(E.filename, O_RDWR | O_CREAT, 0644);
    if (fd != -1) {
        if (ftruncate(fd, len) != -1) {
            if (write(fd, buf, len) == len) {
                close(fd);
                free(buf);
                E.dirty = 0;
                editorSetStatusMessage("%d bytes written to disk", len);
                return;
            }
        }
        close(fd);
    }
    free(buf);
    editorSetStatusMessage("Can't save! I/O error: %s", strerror(errno));
}

有颜色的字符串

enum editorHighlight {
    HL_NORMAL = 0,
    HL_STRING,
    HL_NUMBER,
    HL_MATCH
};

int editorSyntaxToColor(int hl) {
    switch (hl) {
        case HL_STRING: return 35;
        case HL_NUMBER: return 31;
        case HL_MATCH: return 34;
        default: return 37;
    }
}

#define HL_HIGHLIGHT_STRINGS (1<<1)

struct editorSyntax HLDB[] = {
    {
        "c",
        C_HL_extensions,
        HL_HIGHLIGHT_NUMBERS | HL_HIGHLIGHT_STRINGS
    },
};

void editorUpdateSyntax(erow *row) {
    row->hl = realloc(row->hl, row->rsize);
    memset(row->hl, HL_NORMAL, row->rsize);
    if (E.syntax == NULL) return;
    int prev_sep = 1;
    int in_string = 0;//当前字符在字符串里
    int i = 0;
    while (i < row->rsize) {
        char c = row->render[i];
        unsigned char prev_hl = (i > 0) ? row->hl[i - 1] : HL_NORMAL;

        if (E.syntax->flags & HL_HIGHLIGHT_STRINGS) {
            if (in_string) {
                row->hl[i] = HL_STRING;
                //转义符不会关闭字符串
                if (c == '\\' && i + 1 < row->rsize) {
                    row->hl[i + 1] = HL_STRING;
                    i += 2;
                    continue;
                }
                //离开字符串
                if (c == in_string) in_string = 0;
                i++;
                prev_sep = 1;
                continue;
            } else {
                if (c == '"' || c == '\'') {
                    in_string = c;
                    row->hl[i] = HL_STRING;
                    i++;
                    continue;
                }
            }
        }
        if (E.syntax->flags & HL_HIGHLIGHT_NUMBERS) {
            if ((isdigit(c) && (prev_sep || prev_hl == HL_NUMBER)) ||
                (c == '.' && prev_hl == HL_NUMBER)) {
                row->hl[i] = HL_NUMBER;
                i++;
                prev_sep = 0;
                continue;
            }
        }
        prev_sep = is_separator(c);
        i++;
    }
}

有颜色的单行注释

enum editorHighlight {
    HL_NORMAL = 0,
    HL_COMMENT,
    HL_STRING,
    HL_NUMBER,
    HL_MATCH
};

int editorSyntaxToColor(int hl) {
    switch (hl) {
        case HL_COMMENT: return 36;
        case HL_STRING: return 35;
        case HL_NUMBER: return 31;
        case HL_MATCH: return 34;
        default: return 37;
    }
}

struct editorSyntax {
    char *filetype;
    char **filematch;
    char *singleline_comment_start;//单行注释开始
    int flags;
};

char *C_HL_extensions[] = { ".c", ".h", ".cpp", NULL };
struct editorSyntax HLDB[] = {
    {
        "c",
        C_HL_extensions,
        "//",
        HL_HIGHLIGHT_NUMBERS | HL_HIGHLIGHT_STRINGS
    },
};

更新高亮代码

void editorUpdateSyntax(erow *row) {
    row->hl = realloc(row->hl, row->rsize);
    memset(row->hl, HL_NORMAL, row->rsize);
    if (E.syntax == NULL) return;
    
    char *scs = E.syntax->singleline_comment_start;
    int scs_len = scs ? strlen(scs) : 0;//注释部分的长度
    
    int prev_sep = 1;
    int in_string = 0;
    int i = 0;
    while (i < row->rsize) {
        char c = row->render[i];
        unsigned char prev_hl = (i > 0) ? row->hl[i - 1] : HL_NORMAL;
        //设置注释高亮
        if (scs_len && !in_string) {
            if (!strncmp(&row->render[i], scs, scs_len)) {
                memset(&row->hl[i], HL_COMMENT, row->rsize - i);
                break;
            }
        }
        if (E.syntax->flags & HL_HIGHLIGHT_STRINGS) {
            if (in_string) {
                row->hl[i] = HL_STRING;
                if (c == '\\' && i + 1 < row->rsize) {
                    row->hl[i + 1] = HL_STRING;
                    i += 2;
                    continue;
                }
                if (c == in_string) in_string = 0;
                i++;
                prev_sep = 1;
                continue;
            } else {
                if (c == '"' || c == '\'') {
                    in_string = c;
                    row->hl[i] = HL_STRING;
                    i++;
                    continue;
                }
            }
        }
        if (E.syntax->flags & HL_HIGHLIGHT_NUMBERS) {
            if ((isdigit(c) && (prev_sep || prev_hl == HL_NUMBER)) ||
                (c == '.' && prev_hl == HL_NUMBER)) {
                row->hl[i] = HL_NUMBER;
                i++;
                prev_sep = 0;
                continue;
            }
        }
        prev_sep = is_separator(c);
        i++;
    }
}

有颜色的关键字

enum editorHighlight {
    HL_NORMAL = 0,
    HL_COMMENT,
    HL_KEYWORD1,
    HL_KEYWORD2,
    HL_STRING,
    HL_NUMBER,
    HL_MATCH
};

int editorSyntaxToColor(int hl) {
    switch (hl) {
        case HL_COMMENT: return 36;
        case HL_KEYWORD1: return 33;
        case HL_KEYWORD2: return 32;
        case HL_STRING: return 35;
        case HL_NUMBER: return 31;
        case HL_MATCH: return 34;
        default: return 37;
    }
}

struct editorSyntax {
    char *filetype;
    char **filematch;
    char **keywords;
    char *singleline_comment_start;
    int flags;
};
char *C_HL_keywords[] = {
    "switch", "if", "while", "for", "break", "continue", "return", "else",
    "struct", "union", "typedef", "static", "enum", "class", "case",
    "int|", "long|", "double|", "float|", "char|", "unsigned|", "signed|",
    "void|", NULL
};
struct editorSyntax HLDB[] = {
    {
        "c",
        C_HL_extensions,
        C_HL_keywords,
        "//",
        HL_HIGHLIGHT_NUMBERS | HL_HIGHLIGHT_STRINGS
    },
};

void editorUpdateSyntax(erow *row) {
    row->hl = realloc(row->hl, row->rsize);
    memset(row->hl, HL_NORMAL, row->rsize);
    if (E.syntax == NULL) return;
    
    //别名
    char **keywords = E.syntax->keywords;
    
    char *scs = E.syntax->singleline_comment_start;
    int scs_len = scs ? strlen(scs) : 0;
    int prev_sep = 1;
    int in_string = 0;
    int i = 0;
    while (i < row->rsize) {
        char c = row->render[i];
        unsigned char prev_hl = (i > 0) ? row->hl[i - 1] : HL_NORMAL;
        if (scs_len && !in_string) {
            if (!strncmp(&row->render[i], scs, scs_len)) {
                memset(&row->hl[i], HL_COMMENT, row->rsize - i);
                break;
            }
        }
        if (E.syntax->flags & HL_HIGHLIGHT_STRINGS) {
            if (in_string) {
                row->hl[i] = HL_STRING;
                if (c == '\\' && i + 1 < row->rsize) {
                    row->hl[i + 1] = HL_STRING;
                    i += 2;
                    continue;
                }
                if (c == in_string) in_string = 0;
                i++;
                prev_sep = 1;
                continue;
            } else {
                if (c == '"' || c == '\'') {
                    in_string = c;
                    row->hl[i] = HL_STRING;
                    i++;
                    continue;
                }
            }
        }
        if (E.syntax->flags & HL_HIGHLIGHT_NUMBERS) {
            if ((isdigit(c) && (prev_sep || prev_hl == HL_NUMBER)) ||
                (c == '.' && prev_hl == HL_NUMBER)) {
                row->hl[i] = HL_NUMBER;
                i++;
                prev_sep = 0;
                continue;
            }
        }
        
        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 (!strncmp(&row->render[i], keywords[j], klen) &&
                    is_separator(row->render[i + klen])) {
                    //匹配到关键字
                    memset(&row->hl[i], kw2 ? HL_KEYWORD2 : HL_KEYWORD1, klen);
                    i += klen;
                    break;
                }
            }
            if (keywords[j] != NULL) {
                prev_sep = 0;
                continue;
            }
        }
        
        prev_sep = is_separator(c);
        i++;
    }
}

不可打印的字符

即黑块/菱形问号等字符

void editorDrawRows(struct abuf *ab) {
    int y;
    for (y = 0; y < E.screenrows; y++) {
        int filerow = y + E.rowoff;
        if (filerow >= E.numrows) {
            if (E.numrows == 0 && y == E.screenrows / 3) {
                char welcome[80];
                int welcomelen = snprintf(welcome, sizeof(welcome),
                                          "Kilo editor -- version %s", KILO_VERSION);
                if (welcomelen > E.screencols) welcomelen = E.screencols;
                int padding = (E.screencols - welcomelen) / 2;
                if (padding) {
                    abAppend(ab, "~", 1);
                    padding--;
                }
                while (padding--) abAppend(ab, " ", 1);
                abAppend(ab, welcome, welcomelen);
            } else {
                abAppend(ab, "~", 1);
            }
        } else {
            int len = E.row[filerow].rsize - E.coloff;
            if (len < 0) len = 0;
            if (len > E.screencols) len = E.screencols;
            char *c = &E.row[filerow].render[E.coloff];
            unsigned char *hl = &E.row[filerow].hl[E.coloff];
            int current_color = -1;
            int j;
            for (j = 0; j < len; j++) {

                if (iscntrl(c[j])) {
                    char sym = (c[j] <= 26) ? '@' + c[j] : '?';
                    //反转颜色
                    abAppend(ab, "\x1b[7m", 4);
                    abAppend(ab, &sym, 1);
                    abAppend(ab, "\x1b[m", 3);
                    //恢复当前颜色
                    if (current_color != -1) {
                        char buf[16];
                        int clen = snprintf(buf, sizeof(buf), "\x1b[%dm", current_color);
                        abAppend(ab, buf, clen);
                    }
                } 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) {
                        current_color = color;
                        char buf[16];
                        int clen = snprintf(buf, sizeof(buf), "\x1b[%dm", color);
                        abAppend(ab, buf, clen);
                    }
                    abAppend(ab, &c[j], 1);
                }
            }
            abAppend(ab, "\x1b[39m", 5);
        }
        abAppend(ab, "\x1b[K", 3);
        abAppend(ab, "\r\n", 2);
    }
}

有颜色的多行注释

enum editorHighlight {
    HL_NORMAL = 0,
    HL_COMMENT,
    HL_MLCOMMENT,
    HL_KEYWORD1,
    HL_KEYWORD2,
    HL_STRING,
    HL_NUMBER,
    HL_MATCH
};

int editorSyntaxToColor(int hl) {
    switch (hl) {
        case HL_COMMENT:
        case HL_MLCOMMENT: return 36;
        case HL_KEYWORD1: return 33;
        case HL_KEYWORD2: return 32;
        case HL_STRING: return 35;
        case HL_NUMBER: return 31;
        case HL_MATCH: return 34;
        default: return 37;
    }
}

struct editorSyntax {
    char *filetype;
    char **filematch;
    char **keywords;
    char *singleline_comment_start;
    char *multiline_comment_start;
    char *multiline_comment_end;
    int flags;
};

struct editorSyntax HLDB[] = {
    {
        "c",
        C_HL_extensions,
        C_HL_keywords,
        "//", "/*", "*/",
        HL_HIGHLIGHT_NUMBERS | HL_HIGHLIGHT_STRINGS
    },
};

void editorUpdateSyntax(erow *row) {
    row->hl = realloc(row->hl, row->rsize);
    memset(row->hl, HL_NORMAL, row->rsize);
    if (E.syntax == NULL) return;
    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;
    int scs_len = scs ? strlen(scs) : 0;
    int mcs_len = mcs ? strlen(mcs) : 0;
    int mce_len = mce ? strlen(mce) : 0;
    int prev_sep = 1;
    int in_string = 0;
    int in_comment = 0;
    int i = 0;
    while (i < row->rsize) {
        char c = row->render[i];
        unsigned char prev_hl = (i > 0) ? row->hl[i - 1] : HL_NORMAL;
        if (scs_len && !in_string && !in_comment) {//不应在多行注释中检测单行注释
            if (!strncmp(&row->render[i], scs, scs_len)) {
                memset(&row->hl[i], HL_COMMENT, row->rsize - i);
                break;
            }
        }
        
        if (mcs_len && mce_len && !in_string) {
            //在多行注释中
            if (in_comment) {
                row->hl[i] = HL_MLCOMMENT;
                if (!strncmp(&row->render[i], mce, mce_len)) {
                    memset(&row->hl[i], HL_MLCOMMENT, mce_len);
                    i += mce_len;
                    in_comment = 0;
                    prev_sep = 1;
                    continue;
                } else {
                    i++;
                    continue;
                }
            } else if (!strncmp(&row->render[i], mcs, mcs_len)) {
                memset(&row->hl[i], HL_MLCOMMENT, mcs_len);
                i += mcs_len;
                in_comment = 1;
                continue;
            }
        }
        
        if (E.syntax->flags & HL_HIGHLIGHT_STRINGS) {
            if (in_string) {
                row->hl[i] = HL_STRING;
                if (c == '\\' && i + 1 < row->rsize) {
                    row->hl[i + 1] = HL_STRING;
                    i += 2;
                    continue;
                }
                if (c == in_string) in_string = 0;
                i++;
                prev_sep = 1;
                continue;
            } else {
                if (c == '"' || c == '\'') {
                    in_string = c;
                    row->hl[i] = HL_STRING;
                    i++;
                    continue;
                }
            }
        }
        if (E.syntax->flags & HL_HIGHLIGHT_NUMBERS) {
            if ((isdigit(c) && (prev_sep || prev_hl == HL_NUMBER)) ||
                (c == '.' && prev_hl == HL_NUMBER)) {
                row->hl[i] = HL_NUMBER;
                i++;
                prev_sep = 0;
                continue;
            }
        }
        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 (!strncmp(&row->render[i], keywords[j], klen) &&
                    is_separator(row->render[i + klen])) {
                    memset(&row->hl[i], kw2 ? HL_KEYWORD2 : HL_KEYWORD1, klen);
                    i += klen;
                    break;
                }
            }
            if (keywords[j] != NULL) {
                prev_sep = 0;
                continue;
            }
        }
        prev_sep = is_separator(c);
        i++;
    }
}

typedef struct erow {
    int idx;//行的索引
    int size;
    int rsize;
    char *chars;
    char *render;
    unsigned char *hl;
    int hl_open_comment;
} erow;

void editorInsertRow(int at, char *s, size_t len) {
    if (at < 0 || at > E.numrows) return;
    E.row = realloc(E.row, sizeof(erow) * (E.numrows + 1));
    memmove(&E.row[at + 1], &E.row[at], sizeof(erow) * (E.numrows - at));
    //插入一行增加索引
    for (int j = at + 1; j <= E.numrows; j++) E.row[j].idx++;
    E.row[at].idx = at;
    E.row[at].size = len;
    E.row[at].chars = malloc(len + 1);
    memcpy(E.row[at].chars, s, len);
    E.row[at].chars[len] = '\0';
    E.row[at].rsize = 0;
    E.row[at].render = NULL;
    E.row[at].hl = NULL;
    E.row[at].hl_open_comment = 0;
    editorUpdateRow(&E.row[at]);
    E.numrows++;
    E.dirty++;
}

void editorDelRow(int at) {
    if (at < 0 || at >= E.numrows) return;
    editorFreeRow(&E.row[at]);
    memmove(&E.row[at], &E.row[at + 1], sizeof(erow) * (E.numrows - at - 1));
    for (int j = at; j < E.numrows - 1; j++) E.row[j].idx--;
    E.numrows--;
    E.dirty++;
}

void editorUpdateSyntax(erow *row) {
    row->hl = realloc(row->hl, row->rsize);
    memset(row->hl, HL_NORMAL, row->rsize);
    if (E.syntax == NULL) return;
    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;
    int scs_len = scs ? strlen(scs) : 0;
    int mcs_len = mcs ? strlen(mcs) : 0;
    int mce_len = mce ? strlen(mce) : 0;
    int prev_sep = 1;
    int in_string = 0;
    
    int in_comment = (row->idx > 0 && E.row[row->idx - 1].hl_open_comment);
    
    int i = 0;
    while (i < row->rsize) {
        char c = row->render[i];
        unsigned char prev_hl = (i > 0) ? row->hl[i - 1] : HL_NORMAL;
        if (scs_len && !in_string && !in_comment) {
            if (!strncmp(&row->render[i], scs, scs_len)) {
                memset(&row->hl[i], HL_COMMENT, row->rsize - i);
                break;
            }
        }
        if (mcs_len && mce_len && !in_string) {
            if (in_comment) {
                row->hl[i] = HL_MLCOMMENT;
                if (!strncmp(&row->render[i], mce, mce_len)) {
                    memset(&row->hl[i], HL_MLCOMMENT, mce_len);
                    i += mce_len;
                    in_comment = 0;
                    prev_sep = 1;
                    continue;
                } else {
                    i++;
                    continue;
                }
            } else if (!strncmp(&row->render[i], mcs, mcs_len)) {
                memset(&row->hl[i], HL_MLCOMMENT, mcs_len);
                i += mcs_len;
                in_comment = 1;
                continue;
            }
        }
        if (E.syntax->flags & HL_HIGHLIGHT_STRINGS) {
            if (in_string) {
                row->hl[i] = HL_STRING;
                if (c == '\\' && i + 1 < row->rsize) {
                    row->hl[i + 1] = HL_STRING;
                    i += 2;
                    continue;
                }
                if (c == in_string) in_string = 0;
                i++;
                prev_sep = 1;
                continue;
            } else {
                if (c == '"' || c == '\'') {
                    in_string = c;
                    row->hl[i] = HL_STRING;
                    i++;
                    continue;
                }
            }
        }
        if (E.syntax->flags & HL_HIGHLIGHT_NUMBERS) {
            if ((isdigit(c) && (prev_sep || prev_hl == HL_NUMBER)) ||
                (c == '.' && prev_hl == HL_NUMBER)) {
                row->hl[i] = HL_NUMBER;
                i++;
                prev_sep = 0;
                continue;
            }
        }
        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 (!strncmp(&row->render[i], keywords[j], klen) &&
                    is_separator(row->render[i + klen])) {
                    memset(&row->hl[i], kw2 ? HL_KEYWORD2 : HL_KEYWORD1, klen);
                    i += klen;
                    break;
                }
            }
            if (keywords[j] != NULL) {
                prev_sep = 0;
                continue;
            }
        }
        prev_sep = is_separator(c);
        i++;
    }
    
    int changed = (row->hl_open_comment != in_comment);
    row->hl_open_comment = in_comment;
    if (changed && row->idx + 1 < E.numrows)
        editorUpdateSyntax(&E.row[row->idx + 1]);
}

简单升级了下：

char** row_find_offset = NULL;//一行中查找到的词的char*
void editorFindCallback(char *query, int key)
{
	
    static int last_match = -1;
    static int direction = 1;
	static int current_offset = 0;//当前光标指向的row_find_offset里的下标
	static int row_find_count = 0;//当前行找到的个数
	
	static int saved_hl_line;
    static char *saved_hl = NULL;
	if (saved_hl) {
        //如果有保存着的（上个查询的）高亮信息，就把对应的行恢复
        memcpy(E.row[saved_hl_line].hl, saved_hl, E.row[saved_hl_line].rsize);
        free(saved_hl);
        saved_hl = NULL;
    }
	
    if (key == '\r' || key == '\x1b')
	{
        last_match = -1;
        direction = 1;
		current_offset = 0;
		free(row_find_offset);
		row_find_offset = NULL;
		row_find_count = 0;
        return;
    }
	else if (key == ARROW_RIGHT || key == ARROW_DOWN)
	{
        //按右/下键向后搜索
        direction = 1;
    }
	else if (key == ARROW_LEFT || key == ARROW_UP)
	{
        //按左/上键向前搜索
        direction = -1;
    }
	else
	{
        last_match = -1;
        direction = 1;
		current_offset = 0;
		free(row_find_offset);
		row_find_offset = NULL;
		row_find_count = 0;
    }
    
    if (last_match == -1) direction = 1;
    //当前行恢复为上一个匹配行
    int current = last_match;
    
    int i;
    for (i = 0; i < E.numrows; i++)
	{
		erow *row = &E.row[current];
		
		if(key == ARROW_LEFT && current_offset > 0)
		{
			current_offset--;
		}
		else if(key == ARROW_RIGHT && current_offset != row_find_count - 1 && row_find_count != 0)
		{
			current_offset++;
		}
		else
		{
			//当前行不断向上/向下
			//新的一行
			current += direction;
			if (current == -1) current = E.numrows - 1;
			else if (current == E.numrows) current = 0;
			row = &E.row[current];
			
			current_offset = 0;
			if(row_find_offset)
			{
				free(row_find_offset);
				row_find_offset = NULL;
			}
			
			row_find_count = 0;
			
			if(strstr(row->render, query))
			{
				//直接分配rsize个
				row_find_offset = (char**)malloc(sizeof(char*) * row->rsize);
				
				row_find_count = getSubStr(row->render, query, row_find_offset);
			}
			else
			{
				continue;
			}
			
			
		}
		char* match = row_find_offset[current_offset];
		
        if (match)
		{
		
            //上一个匹配行 = 当前行
            last_match = current;
            E.cy = current;
            E.cx = editorRowRxToCx(row, match - row->render);
            E.rowoff = E.numrows;
			
			saved_hl_line = current;
            saved_hl = malloc(row->rsize);
            memcpy(saved_hl, row->hl, row->rsize);
            memset(&row->hl[match - row->render], HL_MATCH, strlen(query));
			
            break;
        }
    }
}



int getSubStr(char* src, char* sub, char** offset)
{
	char* match = src;
	int i = 0;
	while(match)
	{
		match = strstr(match, sub);
		if(!match)
		{
			break;
		}
		offset[i++] = match;
		
		if(strlen(match) >= strlen(sub))
		{
			match += strlen(sub);
		}
	}
	return i;
}