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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