busybox/editors/ed.c
2007-01-29 22:51:00 +00:00

1232 lines
20 KiB
C

/* 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)
*/
#include "busybox.h"
#define USERSIZE 1024 /* max line length typed in by user */
#define INITBUF_SIZE 1024 /* initial buffer size */
typedef struct LINE {
struct LINE *next;
struct LINE *prev;
int len;
char data[1];
} LINE;
static LINE lines, *curLine;
static int curNum, lastNum, marks[26], dirty;
static char *bufBase, *bufPtr, *fileName, searchString[USERSIZE];
static int bufUsed, bufSize;
static void doCommands(void);
static void subCommand(const char *cmd, int num1, int num2);
static int getNum(const char **retcp, int *retHaveNum, int *retNum);
static int setCurNum(int num);
static int initEdit(void);
static void termEdit(void);
static void addLines(int num);
static int insertLine(int num, const char *data, int len);
static int 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);
int ed_main(int argc, char **argv)
{
if (!initEdit())
return EXIT_FAILURE;
if (argc > 1) {
fileName = strdup(argv[1]);
if (fileName == NULL) {
bb_error_msg("no memory");
termEdit();
return EXIT_SUCCESS;
}
if (!readLines(fileName, 1)) {
termEdit();
return EXIT_SUCCESS;
}
if (lastNum)
setCurNum(1);
dirty = FALSE;
}
doCommands();
termEdit();
return EXIT_SUCCESS;
}
/*
* Read commands until we are told to stop.
*/
static void doCommands(void)
{
const char *cp;
char *endbuf, *newname, buf[USERSIZE];
int len, num1, num2, have1, have2;
while (TRUE) {
printf(": ");
fflush(stdout);
if (fgets(buf, sizeof(buf), stdin) == NULL)
return;
len = strlen(buf);
if (len == 0)
return;
endbuf = &buf[len - 1];
if (*endbuf != '\n') {
bb_error_msg("command line too long");
do {
len = fgetc(stdin);
} while ((len != EOF) && (len != '\n'));
continue;
}
while ((endbuf > buf) && isblank(endbuf[-1]))
endbuf--;
*endbuf = '\0';
cp = buf;
while (isblank(*cp))
cp++;
have1 = FALSE;
have2 = FALSE;
if ((curNum == 0) && (lastNum > 0)) {
curNum = 1;
curLine = lines.next;
}
if (!getNum(&cp, &have1, &num1))
continue;
while (isblank(*cp))
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;
}
while (isblank(*cp))
cp++;
if (*cp == '\0') {
if (fileName)
printf("\"%s\"\n", fileName);
else
printf("No file name\n");
break;
}
newname = strdup(cp);
if (newname == NULL) {
bb_error_msg("no memory for file name");
break;
}
if (fileName)
free(fileName);
fileName = newname;
break;
case 'i':
addLines(num1);
break;
case 'k':
while (isblank(*cp))
cp++;
if ((*cp < 'a') || (*cp > 'a') || 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':
while (isblank(*cp))
cp++;
if (have1 || *cp) {
bb_error_msg("bad quit command");
break;
}
if (!dirty)
return;
printf("Really quit? ");
fflush(stdout);
buf[0] = '\0';
fgets(buf, sizeof(buf), stdin);
cp = buf;
while (isblank(*cp))
cp++;
if ((*cp == 'y') || (*cp == 'Y'))
return;
break;
case 'r':
if (*cp && !isblank(*cp)) {
bb_error_msg("bad read command");
break;
}
while (isblank(*cp))
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 = strdup(cp);
break;
case 's':
subCommand(cp, num1, num2);
break;
case 'w':
if (*cp && !isblank(*cp)) {
bb_error_msg("bad write command");
break;
}
while (isblank(*cp))
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 ((num1 < 1) || (num2 > lastNum) || (num1 > num2)) {
bb_error_msg("bad line range for 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 in place of
* the old line structure.
*/
nlp = (LINE *) malloc(sizeof(LINE) + lp->len + deltaLen);
if (nlp == NULL) {
bb_error_msg("cannot get memory for line");
return;
}
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 (fgets(buf, sizeof(buf), stdin)) {
if ((buf[0] == '.') && (buf[1] == '\n') && (buf[2] == '\0'))
return;
len = strlen(buf);
if (len == 0)
return;
if (buf[len - 1] != '\n') {
bb_error_msg("line too long");
do {
len = fgetc(stdin);
} while ((len != EOF) && (len != '\n'));
return;
}
if (!insertLine(num++, buf, len))
return;
}
}
/*
* Parse a line number argument if it is present. This is a sum
* or difference of numbers, '.', '$', 'x, or a search string.
* Returns TRUE if successful (whether or not there was a number).
* Returns FALSE if there was a parsing error, with a message output.
* Whether there was a number is returned indirectly, as is the number.
* The character pointer which stopped the scan is also returned.
*/
static int getNum(const char **retcp, int *retHaveNum, int *retNum)
{
const char *cp;
char *endStr, str[USERSIZE];
int haveNum, value, num, sign;
cp = *retcp;
haveNum = FALSE;
value = 0;
sign = 1;
while (TRUE) {
while (isblank(*cp))
cp++;
switch (*cp) {
case '.':
haveNum = TRUE;
num = curNum;
cp++;
break;
case '$':
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 += num * sign;
while (isblank(*cp))
cp++;
switch (*cp) {
case '-':
sign = -1;
cp++;
break;
case '+':
sign = 1;
cp++;
break;
default:
*retcp = cp;
*retHaveNum = haveNum;
*retNum = value;
return TRUE;
}
}
}
/*
* Initialize everything for editing.
*/
static int initEdit(void)
{
int i;
bufSize = INITBUF_SIZE;
bufBase = malloc(bufSize);
if (bufBase == NULL) {
bb_error_msg("no memory for buffer");
return FALSE;
}
bufPtr = bufBase;
bufUsed = 0;
lines.next = &lines;
lines.prev = &lines;
curLine = NULL;
curNum = 0;
lastNum = 0;
dirty = FALSE;
fileName = NULL;
searchString[0] = '\0';
for (i = 0; i < 26; i++)
marks[i] = 0;
return TRUE;
}
/*
* Finish editing.
*/
static void termEdit(void)
{
if (bufBase)
free(bufBase);
bufBase = NULL;
bufPtr = NULL;
bufSize = 0;
bufUsed = 0;
if (fileName)
free(fileName);
fileName = NULL;
searchString[0] = '\0';
if (lastNum)
deleteLines(1, lastNum);
lastNum = 0;
curNum = 0;
curLine = NULL;
}
/*
* 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) {
perror(file);
return FALSE;
}
bufPtr = bufBase;
bufUsed = 0;
lineCount = 0;
charCount = 0;
cc = 0;
printf("\"%s\", ", file);
fflush(stdout);
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 = realloc(bufBase, len);
if (cp == NULL) {
bb_error_msg("no memory for buffer");
close(fd);
return FALSE;
}
bufBase = cp;
bufPtr = bufBase + bufUsed;
bufSize = len;
}
cc = read(fd, bufPtr, bufSize - bufUsed);
bufUsed += cc;
bufPtr = bufBase;
} while (cc > 0);
if (cc < 0) {
perror(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 ((num1 < 1) || (num2 > lastNum) || (num1 > num2)) {
bb_error_msg("bad line range for write");
return FALSE;
}
lineCount = 0;
charCount = 0;
fd = creat(file, 0666);
if (fd < 0) {
perror(file);
return FALSE;
}
printf("\"%s\", ", file);
fflush(stdout);
lp = findLine(num1);
if (lp == NULL) {
close(fd);
return FALSE;
}
while (num1++ <= num2) {
if (write(fd, lp->data, lp->len) != lp->len) {
perror(file);
close(fd);
return FALSE;
}
charCount += lp->len;
lineCount++;
lp = lp->next;
}
if (close(fd) < 0) {
perror(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 ((num1 < 1) || (num2 > lastNum) || (num1 > num2)) {
bb_error_msg("bad line range for print");
return FALSE;
}
lp = findLine(num1);
if (lp == NULL)
return FALSE;
while (num1 <= num2) {
if (!expandFlag) {
write(1, 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 = *cp++;
if (ch & 0x80) {
fputs("M-", stdout);
ch &= 0x7f;
}
if (ch < ' ') {
fputc('^', stdout);
ch += '@';
}
if (ch == 0x7f) {
fputc('^', stdout);
ch = '?';
}
fputc(ch, 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 = malloc(sizeof(LINE) + len - 1);
if (newLp == NULL) {
bb_error_msg("failed to allocate memory for line");
return FALSE;
}
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 int deleteLines(int num1, int num2)
{
LINE *lp, *nlp, *plp;
int count;
if ((num1 < 1) || (num2 > lastNum) || (num1 > num2)) {
bb_error_msg("bad line numbers for delete");
return FALSE;
}
lp = findLine(num1);
if (lp == NULL)
return FALSE;
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;
lp->next = NULL;
lp->prev = NULL;
lp->len = 0;
free(lp);
lp = nlp;
}
dirty = TRUE;
return TRUE;
}
/*
* Search for a line which contains the specified string.
* If the string is NULL, 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 int searchLines(const char *str, int num1, int num2)
{
const LINE *lp;
int len;
if ((num1 < 1) || (num2 > lastNum) || (num1 > num2)) {
bb_error_msg("bad line numbers for 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("cannot 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;
}