source: MondoRescue/branches/3.3/mindi-busybox/editors/ed.c@ 3621

/* vi: set sw=4 ts=4: */
/*
 * Copyright (c) 2002 by David I. Bell
 * Permission is granted to use, distribute, or modify this source,
 * provided that this copyright notice remains intact.
 *
 * The "ed" built-in command (much simplified)
 */

//config:config ED
//config:   bool "ed"
//config:   default y
//config:   help
//config:     The original 1970's Unix text editor, from the days of teletypes.
//config:     Small, simple, evil. Part of SUSv3. If you're not already using
//config:     this, you don't need it.

//kbuild:lib-$(CONFIG_ED) += ed.o

//applet:IF_ED(APPLET(ed, BB_DIR_BIN, BB_SUID_DROP))

//usage:#define ed_trivial_usage ""
//usage:#define ed_full_usage ""

#include "libbb.h"
#include "common_bufsiz.h"

typedef struct LINE {
    struct LINE *next;
    struct LINE *prev;
    int len;
    char data[1];
} LINE;


#define searchString bb_common_bufsiz1

enum {
    USERSIZE = COMMON_BUFSIZE > 1024 ? 1024
             : COMMON_BUFSIZE - 1, /* max line length typed in by user */
    INITBUF_SIZE = 1024, /* initial buffer size */
};

struct globals {
    int curNum;
    int lastNum;
    int bufUsed;
    int bufSize;
    LINE *curLine;
    char *bufBase;
    char *bufPtr;
    char *fileName;
    LINE lines;
    smallint dirty;
    int marks[26];
};
#define G (*ptr_to_globals)
#define curLine            (G.curLine           )
#define bufBase            (G.bufBase           )
#define bufPtr             (G.bufPtr            )
#define fileName           (G.fileName          )
#define curNum             (G.curNum            )
#define lastNum            (G.lastNum           )
#define bufUsed            (G.bufUsed           )
#define bufSize            (G.bufSize           )
#define dirty              (G.dirty             )
#define lines              (G.lines             )
#define marks              (G.marks             )
#define INIT_G() do { \
    setup_common_bufsiz(); \
    SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
} while (0)


static void doCommands(void);
static void subCommand(const char *cmd, int num1, int num2);
static int getNum(const char **retcp, smallint *retHaveNum, int *retNum);
static int setCurNum(int num);
static void addLines(int num);
static int insertLine(int num, const char *data, int len);
static void deleteLines(int num1, int num2);
static int printLines(int num1, int num2, int expandFlag);
static int writeLines(const char *file, int num1, int num2);
static int readLines(const char *file, int num);
static int searchLines(const char *str, int num1, int num2);
static LINE *findLine(int num);
static int findString(const LINE *lp, const char * str, int len, int offset);


static int bad_nums(int num1, int num2, const char *for_what)
{
    if ((num1 < 1) || (num2 > lastNum) || (num1 > num2)) {
        bb_error_msg("bad line range for %s", for_what);
        return 1;
    }
    return 0;
}


static char *skip_blank(const char *cp)
{
    while (isblank(*cp))
        cp++;
    return (char *)cp;
}


int ed_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int ed_main(int argc UNUSED_PARAM, char **argv)
{
    INIT_G();

    bufSize = INITBUF_SIZE;
    bufBase = xmalloc(bufSize);
    bufPtr = bufBase;
    lines.next = &lines;
    lines.prev = &lines;

    if (argv[1]) {
        fileName = xstrdup(argv[1]);
        if (!readLines(fileName, 1)) {
            return EXIT_SUCCESS;
        }
        if (lastNum)
            setCurNum(1);
        dirty = FALSE;
    }

    doCommands();
    return EXIT_SUCCESS;
}

/*
 * Read commands until we are told to stop.
 */
static void doCommands(void)
{
    const char *cp;
    char *endbuf, buf[USERSIZE];
    int len, num1, num2;
    smallint have1, have2;

    while (TRUE) {
        /* Returns:
         * -1 on read errors or EOF, or on bare Ctrl-D.
         * 0  on ctrl-C,
         * >0 length of input string, including terminating '\n'
         */
        len = read_line_input(NULL, ": ", buf, sizeof(buf), /*timeout*/ -1);
        if (len <= 0)
            return;
        endbuf = &buf[len - 1];
        while ((endbuf > buf) && isblank(endbuf[-1]))
            endbuf--;
        *endbuf = '\0';

        cp = skip_blank(buf);
        have1 = FALSE;
        have2 = FALSE;

        if ((curNum == 0) && (lastNum > 0)) {
            curNum = 1;
            curLine = lines.next;
        }

        if (!getNum(&cp, &have1, &num1))
            continue;

        cp = skip_blank(cp);

        if (*cp == ',') {
            cp++;
            if (!getNum(&cp, &have2, &num2))
                continue;
            if (!have1)
                num1 = 1;
            if (!have2)
                num2 = lastNum;
            have1 = TRUE;
            have2 = TRUE;
        }
        if (!have1)
            num1 = curNum;
        if (!have2)
            num2 = num1;

        switch (*cp++) {
        case 'a':
            addLines(num1 + 1);
            break;

        case 'c':
            deleteLines(num1, num2);
            addLines(num1);
            break;

        case 'd':
            deleteLines(num1, num2);
            break;

        case 'f':
            if (*cp && !isblank(*cp)) {
                bb_error_msg("bad file command");
                break;
            }
            cp = skip_blank(cp);
            if (*cp == '\0') {
                if (fileName)
                    printf("\"%s\"\n", fileName);
                else
                    puts("No file name");
                break;
            }
            free(fileName);
            fileName = xstrdup(cp);
            break;

        case 'i':
            addLines(num1);
            break;

        case 'k':
            cp = skip_blank(cp);
            if ((*cp < 'a') || (*cp > 'z') || cp[1]) {
                bb_error_msg("bad mark name");
                break;
            }
            marks[*cp - 'a'] = num2;
            break;

        case 'l':
            printLines(num1, num2, TRUE);
            break;

        case 'p':
            printLines(num1, num2, FALSE);
            break;

        case 'q':
            cp = skip_blank(cp);
            if (have1 || *cp) {
                bb_error_msg("bad quit command");
                break;
            }
            if (!dirty)
                return;
            len = read_line_input(NULL, "Really quit? ", buf, 16, /*timeout*/ -1);
            /* read error/EOF - no way to continue */
            if (len < 0)
                return;
            cp = skip_blank(buf);
            if ((*cp | 0x20) == 'y') /* Y or y */
                return;
            break;

        case 'r':
            if (*cp && !isblank(*cp)) {
                bb_error_msg("bad read command");
                break;
            }
            cp = skip_blank(cp);
            if (*cp == '\0') {
                bb_error_msg("no file name");
                break;
            }
            if (!have1)
                num1 = lastNum;
            if (readLines(cp, num1 + 1))
                break;
            if (fileName == NULL)
                fileName = xstrdup(cp);
            break;

        case 's':
            subCommand(cp, num1, num2);
            break;

        case 'w':
            if (*cp && !isblank(*cp)) {
                bb_error_msg("bad write command");
                break;
            }
            cp = skip_blank(cp);
            if (!have1) {
                num1 = 1;
                num2 = lastNum;
            }
            if (*cp == '\0')
                cp = fileName;
            if (cp == NULL) {
                bb_error_msg("no file name specified");
                break;
            }
            writeLines(cp, num1, num2);
            break;

        case 'z':
            switch (*cp) {
            case '-':
                printLines(curNum - 21, curNum, FALSE);
                break;
            case '.':
                printLines(curNum - 11, curNum + 10, FALSE);
                break;
            default:
                printLines(curNum, curNum + 21, FALSE);
                break;
            }
            break;

        case '.':
            if (have1) {
                bb_error_msg("no arguments allowed");
                break;
            }
            printLines(curNum, curNum, FALSE);
            break;

        case '-':
            if (setCurNum(curNum - 1))
                printLines(curNum, curNum, FALSE);
            break;

        case '=':
            printf("%d\n", num1);
            break;
        case '\0':
            if (have1) {
                printLines(num2, num2, FALSE);
                break;
            }
            if (setCurNum(curNum + 1))
                printLines(curNum, curNum, FALSE);
            break;

        default:
            bb_error_msg("unimplemented command");
            break;
        }
    }
}


/*
 * Do the substitute command.
 * The current line is set to the last substitution done.
 */
static void subCommand(const char *cmd, int num1, int num2)
{
    char *cp, *oldStr, *newStr, buf[USERSIZE];
    int delim, oldLen, newLen, deltaLen, offset;
    LINE *lp, *nlp;
    int globalFlag, printFlag, didSub, needPrint;

    if (bad_nums(num1, num2, "substitute"))
        return;

    globalFlag = FALSE;
    printFlag = FALSE;
    didSub = FALSE;
    needPrint = FALSE;

    /*
     * Copy the command so we can modify it.
     */
    strcpy(buf, cmd);
    cp = buf;

    if (isblank(*cp) || (*cp == '\0')) {
        bb_error_msg("bad delimiter for substitute");
        return;
    }

    delim = *cp++;
    oldStr = cp;

    cp = strchr(cp, delim);
    if (cp == NULL) {
        bb_error_msg("missing 2nd delimiter for substitute");
        return;
    }

    *cp++ = '\0';

    newStr = cp;
    cp = strchr(cp, delim);

    if (cp)
        *cp++ = '\0';
    else
        cp = (char*)"";

    while (*cp) switch (*cp++) {
        case 'g':
            globalFlag = TRUE;
            break;
        case 'p':
            printFlag = TRUE;
            break;
        default:
            bb_error_msg("unknown option for substitute");
            return;
    }

    if (*oldStr == '\0') {
        if (searchString[0] == '\0') {
            bb_error_msg("no previous search string");
            return;
        }
        oldStr = searchString;
    }

    if (oldStr != searchString)
        strcpy(searchString, oldStr);

    lp = findLine(num1);
    if (lp == NULL)
        return;

    oldLen = strlen(oldStr);
    newLen = strlen(newStr);
    deltaLen = newLen - oldLen;
    offset = 0;
    nlp = NULL;

    while (num1 <= num2) {
        offset = findString(lp, oldStr, oldLen, offset);

        if (offset < 0) {
            if (needPrint) {
                printLines(num1, num1, FALSE);
                needPrint = FALSE;
            }
            offset = 0;
            lp = lp->next;
            num1++;
            continue;
        }

        needPrint = printFlag;
        didSub = TRUE;
        dirty = TRUE;

        /*
         * If the replacement string is the same size or shorter
         * than the old string, then the substitution is easy.
         */
        if (deltaLen <= 0) {
            memcpy(&lp->data[offset], newStr, newLen);
            if (deltaLen) {
                memcpy(&lp->data[offset + newLen],
                    &lp->data[offset + oldLen],
                    lp->len - offset - oldLen);

                lp->len += deltaLen;
            }
            offset += newLen;
            if (globalFlag)
                continue;
            if (needPrint) {
                printLines(num1, num1, FALSE);
                needPrint = FALSE;
            }
            lp = lp->next;
            num1++;
            continue;
        }

        /*
         * The new string is larger, so allocate a new line
         * structure and use that.  Link it in place of
         * the old line structure.
         */
        nlp = xmalloc(sizeof(LINE) + lp->len + deltaLen);

        nlp->len = lp->len + deltaLen;

        memcpy(nlp->data, lp->data, offset);
        memcpy(&nlp->data[offset], newStr, newLen);
        memcpy(&nlp->data[offset + newLen],
            &lp->data[offset + oldLen],
            lp->len - offset - oldLen);

        nlp->next = lp->next;
        nlp->prev = lp->prev;
        nlp->prev->next = nlp;
        nlp->next->prev = nlp;

        if (curLine == lp)
            curLine = nlp;

        free(lp);
        lp = nlp;

        offset += newLen;

        if (globalFlag)
            continue;

        if (needPrint) {
            printLines(num1, num1, FALSE);
            needPrint = FALSE;
        }

        lp = lp->next;
        num1++;
    }

    if (!didSub)
        bb_error_msg("no substitutions found for \"%s\"", oldStr);
}


/*
 * Search a line for the specified string starting at the specified
 * offset in the line.  Returns the offset of the found string, or -1.
 */
static int findString(const LINE *lp, const char *str, int len, int offset)
{
    int left;
    const char *cp, *ncp;

    cp = &lp->data[offset];
    left = lp->len - offset;

    while (left >= len) {
        ncp = memchr(cp, *str, left);
        if (ncp == NULL)
            return -1;
        left -= (ncp - cp);
        if (left < len)
            return -1;
        cp = ncp;
        if (memcmp(cp, str, len) == 0)
            return (cp - lp->data);
        cp++;
        left--;
    }

    return -1;
}


/*
 * Add lines which are typed in by the user.
 * The lines are inserted just before the specified line number.
 * The lines are terminated by a line containing a single dot (ugly!),
 * or by an end of file.
 */
static void addLines(int num)
{
    int len;
    char buf[USERSIZE + 1];

    while (1) {
        /* Returns:
         * -1 on read errors or EOF, or on bare Ctrl-D.
         * 0  on ctrl-C,
         * >0 length of input string, including terminating '\n'
         */
        len = read_line_input(NULL, "", buf, sizeof(buf), /*timeout*/ -1);
        if (len <= 0) {
            /* Previously, ctrl-C was exiting to shell.
             * Now we exit to ed prompt. Is in important? */
            return;
        }
        if ((buf[0] == '.') && (buf[1] == '\n') && (buf[2] == '\0'))
            return;
        if (!insertLine(num++, buf, len))
            return;
    }
}


/*
 * Parse a line number argument if it is present.  This is a sum
 * or difference of numbers, '.', '$', 'x, or a search string.
 * Returns TRUE if successful (whether or not there was a number).
 * Returns FALSE if there was a parsing error, with a message output.
 * Whether there was a number is returned indirectly, as is the number.
 * The character pointer which stopped the scan is also returned.
 */
static int getNum(const char **retcp, smallint *retHaveNum, int *retNum)
{
    const char *cp;
    char *endStr, str[USERSIZE];
    int value, num;
    smallint haveNum, minus;

    cp = *retcp;
    value = 0;
    haveNum = FALSE;
    minus = 0;

    while (TRUE) {
        cp = skip_blank(cp);

        switch (*cp) {
            case '.':
                haveNum = TRUE;
                num = curNum;
                cp++;
                break;

            case '$':
                haveNum = TRUE;
                num = lastNum;
                cp++;
                break;

            case '\'':
                cp++;
                if ((*cp < 'a') || (*cp > 'z')) {
                    bb_error_msg("bad mark name");
                    return FALSE;
                }
                haveNum = TRUE;
                num = marks[*cp++ - 'a'];
                break;

            case '/':
                strcpy(str, ++cp);
                endStr = strchr(str, '/');
                if (endStr) {
                    *endStr++ = '\0';
                    cp += (endStr - str);
                } else
                    cp = "";
                num = searchLines(str, curNum, lastNum);
                if (num == 0)
                    return FALSE;
                haveNum = TRUE;
                break;

            default:
                if (!isdigit(*cp)) {
                    *retcp = cp;
                    *retHaveNum = haveNum;
                    *retNum = value;
                    return TRUE;
                }
                num = 0;
                while (isdigit(*cp))
                    num = num * 10 + *cp++ - '0';
                haveNum = TRUE;
                break;
        }

        value += (minus ? -num : num);

        cp = skip_blank(cp);

        switch (*cp) {
            case '-':
                minus = 1;
                cp++;
                break;

            case '+':
                minus = 0;
                cp++;
                break;

            default:
                *retcp = cp;
                *retHaveNum = haveNum;
                *retNum = value;
                return TRUE;
        }
    }
}


/*
 * Read lines from a file at the specified line number.
 * Returns TRUE if the file was successfully read.
 */
static int readLines(const char *file, int num)
{
    int fd, cc;
    int len, lineCount, charCount;
    char *cp;

    if ((num < 1) || (num > lastNum + 1)) {
        bb_error_msg("bad line for read");
        return FALSE;
    }

    fd = open(file, 0);
    if (fd < 0) {
        bb_simple_perror_msg(file);
        return FALSE;
    }

    bufPtr = bufBase;
    bufUsed = 0;
    lineCount = 0;
    charCount = 0;
    cc = 0;

    printf("\"%s\", ", file);
    fflush_all();

    do {
        cp = memchr(bufPtr, '\n', bufUsed);

        if (cp) {
            len = (cp - bufPtr) + 1;
            if (!insertLine(num, bufPtr, len)) {
                close(fd);
                return FALSE;
            }
            bufPtr += len;
            bufUsed -= len;
            charCount += len;
            lineCount++;
            num++;
            continue;
        }

        if (bufPtr != bufBase) {
            memcpy(bufBase, bufPtr, bufUsed);
            bufPtr = bufBase + bufUsed;
        }

        if (bufUsed >= bufSize) {
            len = (bufSize * 3) / 2;
            cp = xrealloc(bufBase, len);
            bufBase = cp;
            bufPtr = bufBase + bufUsed;
            bufSize = len;
        }

        cc = safe_read(fd, bufPtr, bufSize - bufUsed);
        bufUsed += cc;
        bufPtr = bufBase;
    } while (cc > 0);

    if (cc < 0) {
        bb_simple_perror_msg(file);
        close(fd);
        return FALSE;
    }

    if (bufUsed) {
        if (!insertLine(num, bufPtr, bufUsed)) {
            close(fd);
            return -1;
        }
        lineCount++;
        charCount += bufUsed;
    }

    close(fd);

    printf("%d lines%s, %d chars\n", lineCount,
        (bufUsed ? " (incomplete)" : ""), charCount);

    return TRUE;
}


/*
 * Write the specified lines out to the specified file.
 * Returns TRUE if successful, or FALSE on an error with a message output.
 */
static int writeLines(const char *file, int num1, int num2)
{
    LINE *lp;
    int fd, lineCount, charCount;

    if (bad_nums(num1, num2, "write"))
        return FALSE;

    lineCount = 0;
    charCount = 0;

    fd = creat(file, 0666);
    if (fd < 0) {
        bb_simple_perror_msg(file);
        return FALSE;
    }

    printf("\"%s\", ", file);
    fflush_all();

    lp = findLine(num1);
    if (lp == NULL) {
        close(fd);
        return FALSE;
    }

    while (num1++ <= num2) {
        if (full_write(fd, lp->data, lp->len) != lp->len) {
            bb_simple_perror_msg(file);
            close(fd);
            return FALSE;
        }
        charCount += lp->len;
        lineCount++;
        lp = lp->next;
    }

    if (close(fd) < 0) {
        bb_simple_perror_msg(file);
        return FALSE;
    }

    printf("%d lines, %d chars\n", lineCount, charCount);
    return TRUE;
}


/*
 * Print lines in a specified range.
 * The last line printed becomes the current line.
 * If expandFlag is TRUE, then the line is printed specially to
 * show magic characters.
 */
static int printLines(int num1, int num2, int expandFlag)
{
    const LINE *lp;
    const char *cp;
    int ch, count;

    if (bad_nums(num1, num2, "print"))
        return FALSE;

    lp = findLine(num1);
    if (lp == NULL)
        return FALSE;

    while (num1 <= num2) {
        if (!expandFlag) {
            write(STDOUT_FILENO, lp->data, lp->len);
            setCurNum(num1++);
            lp = lp->next;
            continue;
        }

        /*
         * Show control characters and characters with the
         * high bit set specially.
         */
        cp = lp->data;
        count = lp->len;

        if ((count > 0) && (cp[count - 1] == '\n'))
            count--;

        while (count-- > 0) {
            ch = (unsigned char) *cp++;
            fputc_printable(ch | PRINTABLE_META, stdout);
        }

        fputs("$\n", stdout);

        setCurNum(num1++);
        lp = lp->next;
    }

    return TRUE;
}


/*
 * Insert a new line with the specified text.
 * The line is inserted so as to become the specified line,
 * thus pushing any existing and further lines down one.
 * The inserted line is also set to become the current line.
 * Returns TRUE if successful.
 */
static int insertLine(int num, const char *data, int len)
{
    LINE *newLp, *lp;

    if ((num < 1) || (num > lastNum + 1)) {
        bb_error_msg("inserting at bad line number");
        return FALSE;
    }

    newLp = xmalloc(sizeof(LINE) + len - 1);

    memcpy(newLp->data, data, len);
    newLp->len = len;

    if (num > lastNum)
        lp = &lines;
    else {
        lp = findLine(num);
        if (lp == NULL) {
            free((char *) newLp);
            return FALSE;
        }
    }

    newLp->next = lp;
    newLp->prev = lp->prev;
    lp->prev->next = newLp;
    lp->prev = newLp;

    lastNum++;
    dirty = TRUE;
    return setCurNum(num);
}


/*
 * Delete lines from the given range.
 */
static void deleteLines(int num1, int num2)
{
    LINE *lp, *nlp, *plp;
    int count;

    if (bad_nums(num1, num2, "delete"))
        return;

    lp = findLine(num1);
    if (lp == NULL)
        return;

    if ((curNum >= num1) && (curNum <= num2)) {
        if (num2 < lastNum)
            setCurNum(num2 + 1);
        else if (num1 > 1)
            setCurNum(num1 - 1);
        else
            curNum = 0;
    }

    count = num2 - num1 + 1;
    if (curNum > num2)
        curNum -= count;
    lastNum -= count;

    while (count-- > 0) {
        nlp = lp->next;
        plp = lp->prev;
        plp->next = nlp;
        nlp->prev = plp;
        free(lp);
        lp = nlp;
    }

    dirty = TRUE;
}


/*
 * Search for a line which contains the specified string.
 * If the string is "", then the previously searched for string
 * is used.  The currently searched for string is saved for future use.
 * Returns the line number which matches, or 0 if there was no match
 * with an error printed.
 */
static NOINLINE int searchLines(const char *str, int num1, int num2)
{
    const LINE *lp;
    int len;

    if (bad_nums(num1, num2, "search"))
        return 0;

    if (*str == '\0') {
        if (searchString[0] == '\0') {
            bb_error_msg("no previous search string");
            return 0;
        }
        str = searchString;
    }

    if (str != searchString)
        strcpy(searchString, str);

    len = strlen(str);

    lp = findLine(num1);
    if (lp == NULL)
        return 0;

    while (num1 <= num2) {
        if (findString(lp, str, len, 0) >= 0)
            return num1;
        num1++;
        lp = lp->next;
    }

    bb_error_msg("can't find string \"%s\"", str);
    return 0;
}


/*
 * Return a pointer to the specified line number.
 */
static LINE *findLine(int num)
{
    LINE *lp;
    int lnum;

    if ((num < 1) || (num > lastNum)) {
        bb_error_msg("line number %d does not exist", num);
        return NULL;
    }

    if (curNum <= 0) {
        curNum = 1;
        curLine = lines.next;
    }

    if (num == curNum)
        return curLine;

    lp = curLine;
    lnum = curNum;
    if (num < (curNum / 2)) {
        lp = lines.next;
        lnum = 1;
    } else if (num > ((curNum + lastNum) / 2)) {
        lp = lines.prev;
        lnum = lastNum;
    }

    while (lnum < num) {
        lp = lp->next;
        lnum++;
    }

    while (lnum > num) {
        lp = lp->prev;
        lnum--;
    }
    return lp;
}


/*
 * Set the current line number.
 * Returns TRUE if successful.
 */
static int setCurNum(int num)
{
    LINE *lp;

    lp = findLine(num);
    if (lp == NULL)
        return FALSE;
    curNum = num;
    curLine = lp;
    return TRUE;
}