hush/editors/sed.c
Denys Vlasenko 7b85ec30b5 *: more BUILD_BUG_ON conversions
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2015-10-13 17:17:34 +02:00

1601 lines
42 KiB
C

/* vi: set sw=4 ts=4: */
/*
* sed.c - very minimalist version of sed
*
* Copyright (C) 1999,2000,2001 by Lineo, inc. and Mark Whitley
* Copyright (C) 1999,2000,2001 by Mark Whitley <markw@codepoet.org>
* Copyright (C) 2002 Matt Kraai
* Copyright (C) 2003 by Glenn McGrath
* Copyright (C) 2003,2004 by Rob Landley <rob@landley.net>
*
* MAINTAINER: Rob Landley <rob@landley.net>
*
* Licensed under GPLv2, see file LICENSE in this source tree.
*/
/* Code overview.
*
* Files are laid out to avoid unnecessary function declarations. So for
* example, every function add_cmd calls occurs before add_cmd in this file.
*
* add_cmd() is called on each line of sed command text (from a file or from
* the command line). It calls get_address() and parse_cmd_args(). The
* resulting sed_cmd_t structures are appended to a linked list
* (G.sed_cmd_head/G.sed_cmd_tail).
*
* process_files() does actual sedding, reading data lines from each input FILE*
* (which could be stdin) and applying the sed command list (sed_cmd_head) to
* each of the resulting lines.
*
* sed_main() is where external code calls into this, with a command line.
*/
/* Supported features and commands in this version of sed:
*
* - comments ('#')
* - address matching: num|/matchstr/[,num|/matchstr/|$]command
* - commands: (p)rint, (d)elete, (s)ubstitue (with g & I flags)
* - edit commands: (a)ppend, (i)nsert, (c)hange
* - file commands: (r)ead
* - backreferences in substitution expressions (\0, \1, \2...\9)
* - grouped commands: {cmd1;cmd2}
* - transliteration (y/source-chars/dest-chars/)
* - pattern space hold space storing / swapping (g, h, x)
* - labels / branching (: label, b, t, T)
*
* (Note: Specifying an address (range) to match is *optional*; commands
* default to the whole pattern space if no specific address match was
* requested.)
*
* Todo:
* - Create a wrapper around regex to make libc's regex conform with sed
*
* Reference
* http://www.opengroup.org/onlinepubs/007904975/utilities/sed.html
* http://pubs.opengroup.org/onlinepubs/9699919799/utilities/sed.html
* http://sed.sourceforge.net/sedfaq3.html
*/
//config:config SED
//config: bool "sed"
//config: default y
//config: help
//config: sed is used to perform text transformations on a file
//config: or input from a pipeline.
//kbuild:lib-$(CONFIG_SED) += sed.o
//applet:IF_SED(APPLET(sed, BB_DIR_BIN, BB_SUID_DROP))
//usage:#define sed_trivial_usage
//usage: "[-inrE] [-f FILE]... [-e CMD]... [FILE]...\n"
//usage: "or: sed [-inrE] CMD [FILE]..."
//usage:#define sed_full_usage "\n\n"
//usage: " -e CMD Add CMD to sed commands to be executed"
//usage: "\n -f FILE Add FILE contents to sed commands to be executed"
//usage: "\n -i[SFX] Edit files in-place (otherwise sends to stdout)"
//usage: "\n Optionally back files up, appending SFX"
//usage: "\n -n Suppress automatic printing of pattern space"
//usage: "\n -r,-E Use extended regex syntax"
//usage: "\n"
//usage: "\nIf no -e or -f, the first non-option argument is the sed command string."
//usage: "\nRemaining arguments are input files (stdin if none)."
//usage:
//usage:#define sed_example_usage
//usage: "$ echo \"foo\" | sed -e 's/f[a-zA-Z]o/bar/g'\n"
//usage: "bar\n"
#include "libbb.h"
#include "xregex.h"
#if 0
# define dbg(...) bb_error_msg(__VA_ARGS__)
#else
# define dbg(...) ((void)0)
#endif
enum {
OPT_in_place = 1 << 0,
};
/* Each sed command turns into one of these structures. */
typedef struct sed_cmd_s {
/* Ordered by alignment requirements: currently 36 bytes on x86 */
struct sed_cmd_s *next; /* Next command (linked list, NULL terminated) */
/* address storage */
regex_t *beg_match; /* sed -e '/match/cmd' */
regex_t *end_match; /* sed -e '/match/,/end_match/cmd' */
regex_t *sub_match; /* For 's/sub_match/string/' */
int beg_line; /* 'sed 1p' 0 == apply commands to all lines */
int beg_line_orig; /* copy of the above, needed for -i */
int end_line; /* 'sed 1,3p' 0 == one line only. -1 = last line ($). -2-N = +N */
int end_line_orig;
FILE *sw_file; /* File (sw) command writes to, -1 for none. */
char *string; /* Data string for (saicytb) commands. */
unsigned which_match; /* (s) Which match to replace (0 for all) */
/* Bitfields (gcc won't group them if we don't) */
unsigned invert:1; /* the '!' after the address */
unsigned in_match:1; /* Next line also included in match? */
unsigned sub_p:1; /* (s) print option */
char sw_last_char; /* Last line written by (sw) had no '\n' */
/* GENERAL FIELDS */
char cmd; /* The command char: abcdDgGhHilnNpPqrstwxy:={} */
} sed_cmd_t;
static const char semicolon_whitespace[] ALIGN1 = "; \n\r\t\v";
struct globals {
/* options */
int be_quiet, regex_type;
FILE *nonstdout;
char *outname, *hold_space;
smallint exitcode;
/* list of input files */
int current_input_file, last_input_file;
char **input_file_list;
FILE *current_fp;
regmatch_t regmatch[10];
regex_t *previous_regex_ptr;
/* linked list of sed commands */
sed_cmd_t *sed_cmd_head, **sed_cmd_tail;
/* linked list of append lines */
llist_t *append_head;
char *add_cmd_line;
struct pipeline {
char *buf; /* Space to hold string */
int idx; /* Space used */
int len; /* Space allocated */
} pipeline;
} FIX_ALIASING;
#define G (*(struct globals*)&bb_common_bufsiz1)
#define INIT_G() do { \
BUILD_BUG_ON(sizeof(G) > COMMON_BUFSIZE); \
G.sed_cmd_tail = &G.sed_cmd_head; \
} while (0)
#if ENABLE_FEATURE_CLEAN_UP
static void sed_free_and_close_stuff(void)
{
sed_cmd_t *sed_cmd = G.sed_cmd_head;
llist_free(G.append_head, free);
while (sed_cmd) {
sed_cmd_t *sed_cmd_next = sed_cmd->next;
if (sed_cmd->sw_file)
xprint_and_close_file(sed_cmd->sw_file);
if (sed_cmd->beg_match) {
regfree(sed_cmd->beg_match);
free(sed_cmd->beg_match);
}
if (sed_cmd->end_match) {
regfree(sed_cmd->end_match);
free(sed_cmd->end_match);
}
if (sed_cmd->sub_match) {
regfree(sed_cmd->sub_match);
free(sed_cmd->sub_match);
}
free(sed_cmd->string);
free(sed_cmd);
sed_cmd = sed_cmd_next;
}
free(G.hold_space);
if (G.current_fp)
fclose(G.current_fp);
}
#else
void sed_free_and_close_stuff(void);
#endif
/* If something bad happens during -i operation, delete temp file */
static void cleanup_outname(void)
{
if (G.outname) unlink(G.outname);
}
/* strcpy, replacing "\from" with 'to'. If to is NUL, replacing "\any" with 'any' */
static void parse_escapes(char *dest, const char *string, int len, char from, char to)
{
int i = 0;
while (i < len) {
if (string[i] == '\\') {
if (!to || string[i+1] == from) {
*dest++ = to ? to : string[i+1];
i += 2;
continue;
}
*dest++ = string[i++];
}
/* TODO: is it safe wrt a string with trailing '\\' ? */
*dest++ = string[i++];
}
*dest = '\0';
}
static char *copy_parsing_escapes(const char *string, int len)
{
const char *s;
char *dest = xmalloc(len + 1);
/* sed recognizes \n */
/* GNU sed also recognizes \t and \r */
for (s = "\nn\tt\rr"; *s; s += 2) {
parse_escapes(dest, string, len, s[1], s[0]);
string = dest;
len = strlen(dest);
}
return dest;
}
/*
* index_of_next_unescaped_regexp_delim - walks left to right through a string
* beginning at a specified index and returns the index of the next regular
* expression delimiter (typically a forward slash ('/')) not preceded by
* a backslash ('\'). A negative delimiter disables square bracket checking.
*/
static int index_of_next_unescaped_regexp_delim(int delimiter, const char *str)
{
int bracket = -1;
int escaped = 0;
int idx = 0;
char ch;
if (delimiter < 0) {
bracket--;
delimiter = -delimiter;
}
for (; (ch = str[idx]) != '\0'; idx++) {
if (bracket >= 0) {
if (ch == ']'
&& !(bracket == idx - 1 || (bracket == idx - 2 && str[idx - 1] == '^'))
) {
bracket = -1;
}
} else if (escaped)
escaped = 0;
else if (ch == '\\')
escaped = 1;
else if (bracket == -1 && ch == '[')
bracket = idx;
else if (ch == delimiter)
return idx;
}
/* if we make it to here, we've hit the end of the string */
bb_error_msg_and_die("unmatched '%c'", delimiter);
}
/*
* Returns the index of the third delimiter
*/
static int parse_regex_delim(const char *cmdstr, char **match, char **replace)
{
const char *cmdstr_ptr = cmdstr;
unsigned char delimiter;
int idx = 0;
/* verify that the 's' or 'y' is followed by something. That something
* (typically a 'slash') is now our regexp delimiter... */
if (*cmdstr == '\0')
bb_error_msg_and_die("bad format in substitution expression");
delimiter = *cmdstr_ptr++;
/* save the match string */
idx = index_of_next_unescaped_regexp_delim(delimiter, cmdstr_ptr);
*match = copy_parsing_escapes(cmdstr_ptr, idx);
/* save the replacement string */
cmdstr_ptr += idx + 1;
idx = index_of_next_unescaped_regexp_delim(- (int)delimiter, cmdstr_ptr);
*replace = copy_parsing_escapes(cmdstr_ptr, idx);
return ((cmdstr_ptr - cmdstr) + idx);
}
/*
* returns the index in the string just past where the address ends.
*/
static int get_address(const char *my_str, int *linenum, regex_t ** regex)
{
const char *pos = my_str;
if (isdigit(*my_str)) {
*linenum = strtol(my_str, (char**)&pos, 10);
/* endstr shouldnt ever equal NULL */
} else if (*my_str == '$') {
*linenum = -1;
pos++;
} else if (*my_str == '/' || *my_str == '\\') {
int next;
char delimiter;
char *temp;
delimiter = '/';
if (*my_str == '\\')
delimiter = *++pos;
next = index_of_next_unescaped_regexp_delim(delimiter, ++pos);
temp = copy_parsing_escapes(pos, next);
*regex = xzalloc(sizeof(regex_t));
xregcomp(*regex, temp, G.regex_type);
free(temp);
/* Move position to next character after last delimiter */
pos += (next+1);
}
return pos - my_str;
}
/* Grab a filename. Whitespace at start is skipped, then goes to EOL. */
static int parse_file_cmd(/*sed_cmd_t *sed_cmd,*/ const char *filecmdstr, char **retval)
{
int start = 0, idx, hack = 0;
/* Skip whitespace, then grab filename to end of line */
while (isspace(filecmdstr[start]))
start++;
idx = start;
while (filecmdstr[idx] && filecmdstr[idx] != '\n')
idx++;
/* If lines glued together, put backslash back. */
if (filecmdstr[idx] == '\n')
hack = 1;
if (idx == start)
bb_error_msg_and_die("empty filename");
*retval = xstrndup(filecmdstr+start, idx-start+hack+1);
if (hack)
(*retval)[idx] = '\\';
return idx;
}
static int parse_subst_cmd(sed_cmd_t *sed_cmd, const char *substr)
{
int cflags = G.regex_type;
char *match;
int idx;
/*
* A substitution command should look something like this:
* s/match/replace/ #giIpw
* || | |||
* mandatory optional
*/
idx = parse_regex_delim(substr, &match, &sed_cmd->string);
/* determine the number of back references in the match string */
/* Note: we compute this here rather than in the do_subst_command()
* function to save processor time, at the expense of a little more memory
* (4 bits) per sed_cmd */
/* process the flags */
sed_cmd->which_match = 1;
dbg("s flags:'%s'", substr + idx + 1);
while (substr[++idx]) {
dbg("s flag:'%c'", substr[idx]);
/* Parse match number */
if (isdigit(substr[idx])) {
if (match[0] != '^') {
/* Match 0 treated as all, multiple matches we take the last one. */
const char *pos = substr + idx;
/* FIXME: error check? */
sed_cmd->which_match = (unsigned)strtol(substr+idx, (char**) &pos, 10);
idx = pos - substr - 1;
}
continue;
}
/* Skip spaces */
if (isspace(substr[idx]))
continue;
switch (substr[idx]) {
/* Replace all occurrences */
case 'g':
if (match[0] != '^')
sed_cmd->which_match = 0;
break;
/* Print pattern space */
case 'p':
sed_cmd->sub_p = 1;
break;
/* Write to file */
case 'w':
{
char *temp;
idx += parse_file_cmd(/*sed_cmd,*/ substr+idx, &temp);
break;
}
/* Ignore case (gnu exension) */
case 'i':
case 'I':
cflags |= REG_ICASE;
break;
/* Comment */
case '#':
// while (substr[++idx]) continue;
idx += strlen(substr + idx); // same
/* Fall through */
/* End of command */
case ';':
case '}':
goto out;
default:
dbg("s bad flags:'%s'", substr + idx);
bb_error_msg_and_die("bad option in substitution expression");
}
}
out:
/* compile the match string into a regex */
if (*match != '\0') {
/* If match is empty, we use last regex used at runtime */
sed_cmd->sub_match = xzalloc(sizeof(regex_t));
dbg("xregcomp('%s',%x)", match, cflags);
xregcomp(sed_cmd->sub_match, match, cflags);
dbg("regcomp ok");
}
free(match);
return idx;
}
/*
* Process the commands arguments
*/
static const char *parse_cmd_args(sed_cmd_t *sed_cmd, const char *cmdstr)
{
static const char cmd_letters[] = "saicrw:btTydDgGhHlnNpPqx={}";
enum {
IDX_s = 0,
IDX_a,
IDX_i,
IDX_c,
IDX_r,
IDX_w,
IDX_colon,
IDX_b,
IDX_t,
IDX_T,
IDX_y,
IDX_d,
IDX_D,
IDX_g,
IDX_G,
IDX_h,
IDX_H,
IDX_l,
IDX_n,
IDX_N,
IDX_p,
IDX_P,
IDX_q,
IDX_x,
IDX_equal,
IDX_lbrace,
IDX_rbrace,
IDX_nul
};
unsigned idx;
BUILD_BUG_ON(sizeof(cmd_letters)-1 != IDX_nul);
idx = strchrnul(cmd_letters, sed_cmd->cmd) - cmd_letters;
/* handle (s)ubstitution command */
if (idx == IDX_s) {
cmdstr += parse_subst_cmd(sed_cmd, cmdstr);
}
/* handle edit cmds: (a)ppend, (i)nsert, and (c)hange */
else if (idx <= IDX_c) { /* a,i,c */
if (idx < IDX_c) { /* a,i */
if (sed_cmd->end_line || sed_cmd->end_match)
bb_error_msg_and_die("command '%c' uses only one address", sed_cmd->cmd);
}
for (;;) {
if (*cmdstr == '\n' || *cmdstr == '\\') {
cmdstr++;
break;
}
if (!isspace(*cmdstr))
break;
cmdstr++;
}
sed_cmd->string = xstrdup(cmdstr);
/* "\anychar" -> "anychar" */
parse_escapes(sed_cmd->string, sed_cmd->string, strlen(cmdstr), '\0', '\0');
cmdstr += strlen(cmdstr);
}
/* handle file cmds: (r)ead */
else if (idx <= IDX_w) { /* r,w */
if (idx < IDX_w) { /* r */
if (sed_cmd->end_line || sed_cmd->end_match)
bb_error_msg_and_die("command '%c' uses only one address", sed_cmd->cmd);
}
cmdstr += parse_file_cmd(/*sed_cmd,*/ cmdstr, &sed_cmd->string);
if (sed_cmd->cmd == 'w') {
sed_cmd->sw_file = xfopen_for_write(sed_cmd->string);
sed_cmd->sw_last_char = '\n';
}
}
/* handle branch commands */
else if (idx <= IDX_T) { /* :,b,t,T */
int length;
cmdstr = skip_whitespace(cmdstr);
length = strcspn(cmdstr, semicolon_whitespace);
if (length) {
sed_cmd->string = xstrndup(cmdstr, length);
cmdstr += length;
}
}
/* translation command */
else if (idx == IDX_y) {
char *match, *replace;
int i = cmdstr[0];
cmdstr += parse_regex_delim(cmdstr, &match, &replace)+1;
/* \n already parsed, but \delimiter needs unescaping. */
parse_escapes(match, match, strlen(match), i, i);
parse_escapes(replace, replace, strlen(replace), i, i);
sed_cmd->string = xzalloc((strlen(match) + 1) * 2);
for (i = 0; match[i] && replace[i]; i++) {
sed_cmd->string[i*2] = match[i];
sed_cmd->string[i*2+1] = replace[i];
}
free(match);
free(replace);
}
/* if it wasnt a single-letter command that takes no arguments
* then it must be an invalid command.
*/
else if (idx >= IDX_nul) { /* not d,D,g,G,h,H,l,n,N,p,P,q,x,=,{,} */
bb_error_msg_and_die("unsupported command %c", sed_cmd->cmd);
}
/* give back whatever's left over */
return cmdstr;
}
/* Parse address+command sets, skipping comment lines. */
static void add_cmd(const char *cmdstr)
{
sed_cmd_t *sed_cmd;
unsigned len, n;
/* Append this line to any unfinished line from last time. */
if (G.add_cmd_line) {
char *tp = xasprintf("%s\n%s", G.add_cmd_line, cmdstr);
free(G.add_cmd_line);
cmdstr = G.add_cmd_line = tp;
}
/* If this line ends with unescaped backslash, request next line. */
n = len = strlen(cmdstr);
while (n && cmdstr[n-1] == '\\')
n--;
if ((len - n) & 1) { /* if odd number of trailing backslashes */
if (!G.add_cmd_line)
G.add_cmd_line = xstrdup(cmdstr);
G.add_cmd_line[len-1] = '\0';
return;
}
/* Loop parsing all commands in this line. */
while (*cmdstr) {
/* Skip leading whitespace and semicolons */
cmdstr += strspn(cmdstr, semicolon_whitespace);
/* If no more commands, exit. */
if (!*cmdstr) break;
/* if this is a comment, jump past it and keep going */
if (*cmdstr == '#') {
/* "#n" is the same as using -n on the command line */
if (cmdstr[1] == 'n')
G.be_quiet++;
cmdstr = strpbrk(cmdstr, "\n\r");
if (!cmdstr) break;
continue;
}
/* parse the command
* format is: [addr][,addr][!]cmd
* |----||-----||-|
* part1 part2 part3
*/
sed_cmd = xzalloc(sizeof(sed_cmd_t));
/* first part (if present) is an address: either a '$', a number or a /regex/ */
cmdstr += get_address(cmdstr, &sed_cmd->beg_line, &sed_cmd->beg_match);
sed_cmd->beg_line_orig = sed_cmd->beg_line;
/* second part (if present) will begin with a comma */
if (*cmdstr == ',') {
int idx;
cmdstr++;
if (*cmdstr == '+' && isdigit(cmdstr[1])) {
/* http://sed.sourceforge.net/sedfaq3.html#s3.3
* Under GNU sed 3.02+, ssed, and sed15+, <address2>
* may also be a notation of the form +num,
* indicating the next num lines after <address1> is
* matched.
* GNU sed 4.2.1 accepts even "+" (meaning "+0").
* We don't (we check for isdigit, see above), think
* about the "+-3" case.
*/
char *end;
/* code is smaller compared to using &cmdstr here: */
idx = strtol(cmdstr+1, &end, 10);
sed_cmd->end_line = -2 - idx;
cmdstr = end;
} else {
idx = get_address(cmdstr, &sed_cmd->end_line, &sed_cmd->end_match);
cmdstr += idx;
idx--; /* if 0, trigger error check below */
}
if (idx < 0)
bb_error_msg_and_die("no address after comma");
sed_cmd->end_line_orig = sed_cmd->end_line;
}
/* skip whitespace before the command */
cmdstr = skip_whitespace(cmdstr);
/* Check for inversion flag */
if (*cmdstr == '!') {
sed_cmd->invert = 1;
cmdstr++;
/* skip whitespace before the command */
cmdstr = skip_whitespace(cmdstr);
}
/* last part (mandatory) will be a command */
if (!*cmdstr)
bb_error_msg_and_die("missing command");
sed_cmd->cmd = *cmdstr++;
cmdstr = parse_cmd_args(sed_cmd, cmdstr);
/* cmdstr now points past args.
* GNU sed requires a separator, if there are more commands,
* else it complains "char N: extra characters after command".
* Example: "sed 'p;d'". We also allow "sed 'pd'".
*/
/* Add the command to the command array */
*G.sed_cmd_tail = sed_cmd;
G.sed_cmd_tail = &sed_cmd->next;
}
/* If we glued multiple lines together, free the memory. */
free(G.add_cmd_line);
G.add_cmd_line = NULL;
}
/* Append to a string, reallocating memory as necessary. */
#define PIPE_GROW 64
static void pipe_putc(char c)
{
if (G.pipeline.idx == G.pipeline.len) {
G.pipeline.buf = xrealloc(G.pipeline.buf,
G.pipeline.len + PIPE_GROW);
G.pipeline.len += PIPE_GROW;
}
G.pipeline.buf[G.pipeline.idx++] = c;
}
static void do_subst_w_backrefs(char *line, char *replace)
{
int i, j;
/* go through the replacement string */
for (i = 0; replace[i]; i++) {
/* if we find a backreference (\1, \2, etc.) print the backref'ed text */
if (replace[i] == '\\') {
unsigned backref = replace[++i] - '0';
if (backref <= 9) {
/* print out the text held in G.regmatch[backref] */
if (G.regmatch[backref].rm_so != -1) {
j = G.regmatch[backref].rm_so;
while (j < G.regmatch[backref].rm_eo)
pipe_putc(line[j++]);
}
continue;
}
/* I _think_ it is impossible to get '\' to be
* the last char in replace string. Thus we dont check
* for replace[i] == NUL. (counterexample anyone?) */
/* if we find a backslash escaped character, print the character */
pipe_putc(replace[i]);
continue;
}
/* if we find an unescaped '&' print out the whole matched text. */
if (replace[i] == '&') {
j = G.regmatch[0].rm_so;
while (j < G.regmatch[0].rm_eo)
pipe_putc(line[j++]);
continue;
}
/* Otherwise just output the character. */
pipe_putc(replace[i]);
}
}
static int do_subst_command(sed_cmd_t *sed_cmd, char **line_p)
{
char *line = *line_p;
unsigned match_count = 0;
bool altered = 0;
bool prev_match_empty = 1;
bool tried_at_eol = 0;
regex_t *current_regex;
current_regex = sed_cmd->sub_match;
/* Handle empty regex. */
if (!current_regex) {
current_regex = G.previous_regex_ptr;
if (!current_regex)
bb_error_msg_and_die("no previous regexp");
}
G.previous_regex_ptr = current_regex;
/* Find the first match */
dbg("matching '%s'", line);
if (REG_NOMATCH == regexec(current_regex, line, 10, G.regmatch, 0)) {
dbg("no match");
return 0;
}
dbg("match");
/* Initialize temporary output buffer. */
G.pipeline.buf = xmalloc(PIPE_GROW);
G.pipeline.len = PIPE_GROW;
G.pipeline.idx = 0;
/* Now loop through, substituting for matches */
do {
int start = G.regmatch[0].rm_so;
int end = G.regmatch[0].rm_eo;
int i;
match_count++;
/* If we aren't interested in this match, output old line to
* end of match and continue */
if (sed_cmd->which_match
&& (sed_cmd->which_match != match_count)
) {
for (i = 0; i < end; i++)
pipe_putc(*line++);
/* Null match? Print one more char */
if (start == end && *line)
pipe_putc(*line++);
goto next;
}
/* Print everything before the match */
for (i = 0; i < start; i++)
pipe_putc(line[i]);
/* Then print the substitution string,
* unless we just matched empty string after non-empty one.
* Example: string "cccd", pattern "c*", repl "R":
* result is "RdR", not "RRdR": first match "ccc",
* second is "" before "d", third is "" after "d".
* Second match is NOT replaced!
*/
if (prev_match_empty || start != 0 || start != end) {
//dbg("%d %d %d", prev_match_empty, start, end);
dbg("inserting replacement at %d in '%s'", start, line);
do_subst_w_backrefs(line, sed_cmd->string);
/* Flag that something has changed */
altered = 1;
} else {
dbg("NOT inserting replacement at %d in '%s'", start, line);
}
/* If matched string is empty (f.e. "c*" pattern),
* copy verbatim one char after it before attempting more matches
*/
prev_match_empty = (start == end);
if (prev_match_empty) {
if (!line[end]) {
tried_at_eol = 1;
} else {
pipe_putc(line[end]);
end++;
}
}
/* Advance past the match */
dbg("line += %d", end);
line += end;
/* if we're not doing this globally, get out now */
if (sed_cmd->which_match != 0)
break;
next:
/* Exit if we are at EOL and already tried matching at it */
if (*line == '\0') {
if (tried_at_eol)
break;
tried_at_eol = 1;
}
//maybe (end ? REG_NOTBOL : 0) instead of unconditional REG_NOTBOL?
} while (regexec(current_regex, line, 10, G.regmatch, REG_NOTBOL) != REG_NOMATCH);
/* Copy rest of string into output pipeline */
while (1) {
char c = *line++;
pipe_putc(c);
if (c == '\0')
break;
}
free(*line_p);
*line_p = G.pipeline.buf;
return altered;
}
/* Set command pointer to point to this label. (Does not handle null label.) */
static sed_cmd_t *branch_to(char *label)
{
sed_cmd_t *sed_cmd;
for (sed_cmd = G.sed_cmd_head; sed_cmd; sed_cmd = sed_cmd->next) {
if (sed_cmd->cmd == ':' && sed_cmd->string && !strcmp(sed_cmd->string, label)) {
return sed_cmd;
}
}
bb_error_msg_and_die("can't find label for jump to '%s'", label);
}
static void append(char *s)
{
llist_add_to_end(&G.append_head, s);
}
/* Output line of text. */
/* Note:
* The tricks with NO_EOL_CHAR and last_puts_char are there to emulate gnu sed.
* Without them, we had this:
* echo -n thingy >z1
* echo -n again >z2
* >znull
* sed "s/i/z/" z1 z2 znull | hexdump -vC
* output:
* gnu sed 4.1.5:
* 00000000 74 68 7a 6e 67 79 0a 61 67 61 7a 6e |thzngy.agazn|
* bbox:
* 00000000 74 68 7a 6e 67 79 61 67 61 7a 6e |thzngyagazn|
*/
enum {
NO_EOL_CHAR = 1,
LAST_IS_NUL = 2,
};
static void puts_maybe_newline(char *s, FILE *file, char *last_puts_char, char last_gets_char)
{
char lpc = *last_puts_char;
/* Need to insert a '\n' between two files because first file's
* last line wasn't terminated? */
if (lpc != '\n' && lpc != '\0') {
fputc('\n', file);
lpc = '\n';
}
fputs(s, file);
/* 'x' - just something which is not '\n', '\0' or NO_EOL_CHAR */
if (s[0])
lpc = 'x';
/* had trailing '\0' and it was last char of file? */
if (last_gets_char == LAST_IS_NUL) {
fputc('\0', file);
lpc = 'x'; /* */
} else
/* had trailing '\n' or '\0'? */
if (last_gets_char != NO_EOL_CHAR) {
fputc(last_gets_char, file);
lpc = last_gets_char;
}
if (ferror(file)) {
xfunc_error_retval = 4; /* It's what gnu sed exits with... */
bb_error_msg_and_die(bb_msg_write_error);
}
*last_puts_char = lpc;
}
static void flush_append(char *last_puts_char, char last_gets_char)
{
char *data;
/* Output appended lines. */
while ((data = (char *)llist_pop(&G.append_head))) {
puts_maybe_newline(data, G.nonstdout, last_puts_char, last_gets_char);
free(data);
}
}
/* Get next line of input from G.input_file_list, flushing append buffer and
* noting if we ran out of files without a newline on the last line we read.
*/
static char *get_next_line(char *gets_char, char *last_puts_char, char last_gets_char)
{
char *temp = NULL;
int len;
char gc;
flush_append(last_puts_char, last_gets_char);
/* will be returned if last line in the file
* doesn't end with either '\n' or '\0' */
gc = NO_EOL_CHAR;
for (; G.current_input_file <= G.last_input_file; G.current_input_file++) {
FILE *fp = G.current_fp;
if (!fp) {
const char *path = G.input_file_list[G.current_input_file];
fp = stdin;
if (path != bb_msg_standard_input) {
fp = fopen_or_warn(path, "r");
if (!fp) {
G.exitcode = EXIT_FAILURE;
continue;
}
}
G.current_fp = fp;
}
/* Read line up to a newline or NUL byte, inclusive,
* return malloc'ed char[]. length of the chunk read
* is stored in len. NULL if EOF/error */
temp = bb_get_chunk_from_file(fp, &len);
if (temp) {
/* len > 0 here, it's ok to do temp[len-1] */
char c = temp[len-1];
if (c == '\n' || c == '\0') {
temp[len-1] = '\0';
gc = c;
if (c == '\0') {
int ch = fgetc(fp);
if (ch != EOF)
ungetc(ch, fp);
else
gc = LAST_IS_NUL;
}
}
/* else we put NO_EOL_CHAR into *gets_char */
break;
/* NB: I had the idea of peeking next file(s) and returning
* NO_EOL_CHAR only if it is the *last* non-empty
* input file. But there is a case where this won't work:
* file1: "a woo\nb woo"
* file2: "c no\nd no"
* sed -ne 's/woo/bang/p' input1 input2 => "a bang\nb bang"
* (note: *no* newline after "b bang"!) */
}
/* Close this file and advance to next one */
fclose_if_not_stdin(fp);
G.current_fp = NULL;
}
*gets_char = gc;
return temp;
}
#define sed_puts(s, n) (puts_maybe_newline(s, G.nonstdout, &last_puts_char, n))
static int beg_match(sed_cmd_t *sed_cmd, const char *pattern_space)
{
int retval = sed_cmd->beg_match && !regexec(sed_cmd->beg_match, pattern_space, 0, NULL, 0);
if (retval)
G.previous_regex_ptr = sed_cmd->beg_match;
return retval;
}
/* Process all the lines in all the files */
static void process_files(void)
{
char *pattern_space, *next_line;
int linenum = 0;
char last_puts_char = '\n';
char last_gets_char, next_gets_char;
sed_cmd_t *sed_cmd;
int substituted;
/* Prime the pump */
next_line = get_next_line(&next_gets_char, &last_puts_char, '\n' /*last_gets_char*/);
/* Go through every line in each file */
again:
substituted = 0;
/* Advance to next line. Stop if out of lines. */
pattern_space = next_line;
if (!pattern_space)
return;
last_gets_char = next_gets_char;
/* Read one line in advance so we can act on the last line,
* the '$' address */
next_line = get_next_line(&next_gets_char, &last_puts_char, last_gets_char);
linenum++;
/* For every line, go through all the commands */
restart:
for (sed_cmd = G.sed_cmd_head; sed_cmd; sed_cmd = sed_cmd->next) {
int old_matched, matched;
old_matched = sed_cmd->in_match;
/* Determine if this command matches this line: */
dbg("match1:%d", sed_cmd->in_match);
dbg("match2:%d", (!sed_cmd->beg_line && !sed_cmd->end_line
&& !sed_cmd->beg_match && !sed_cmd->end_match));
dbg("match3:%d", (sed_cmd->beg_line > 0
&& (sed_cmd->end_line || sed_cmd->end_match
? (sed_cmd->beg_line <= linenum)
: (sed_cmd->beg_line == linenum)
)
));
dbg("match4:%d", (beg_match(sed_cmd, pattern_space)));
dbg("match5:%d", (sed_cmd->beg_line == -1 && next_line == NULL));
/* Are we continuing a previous multi-line match? */
sed_cmd->in_match = sed_cmd->in_match
/* Or is no range necessary? */
|| (!sed_cmd->beg_line && !sed_cmd->end_line
&& !sed_cmd->beg_match && !sed_cmd->end_match)
/* Or did we match the start of a numerical range? */
|| (sed_cmd->beg_line > 0
&& (sed_cmd->end_line || sed_cmd->end_match
/* note: even if end is numeric and is < linenum too,
* GNU sed matches! We match too, therefore we don't
* check here that linenum <= end.
* Example:
* printf '1\n2\n3\n4\n' | sed -n '1{N;N;d};1p;2,3p;3p;4p'
* first three input lines are deleted;
* 4th line is matched and printed
* by "2,3" (!) and by "4" ranges
*/
? (sed_cmd->beg_line <= linenum) /* N,end */
: (sed_cmd->beg_line == linenum) /* N */
)
)
/* Or does this line match our begin address regex? */
|| (beg_match(sed_cmd, pattern_space))
/* Or did we match last line of input? */
|| (sed_cmd->beg_line == -1 && next_line == NULL);
/* Snapshot the value */
matched = sed_cmd->in_match;
dbg("cmd:'%c' matched:%d beg_line:%d end_line:%d linenum:%d",
sed_cmd->cmd, matched, sed_cmd->beg_line, sed_cmd->end_line, linenum);
/* Is this line the end of the current match? */
if (matched) {
if (sed_cmd->end_line <= -2) {
/* address2 is +N, i.e. N lines from beg_line */
sed_cmd->end_line = linenum + (-sed_cmd->end_line - 2);
}
/* once matched, "n,xxx" range is dead, disabling it */
if (sed_cmd->beg_line > 0) {
sed_cmd->beg_line = -2;
}
dbg("end1:%d", sed_cmd->end_line ? sed_cmd->end_line == -1
? !next_line : (sed_cmd->end_line <= linenum)
: !sed_cmd->end_match);
dbg("end2:%d", sed_cmd->end_match && old_matched
&& !regexec(sed_cmd->end_match,pattern_space, 0, NULL, 0));
sed_cmd->in_match = !(
/* has the ending line come, or is this a single address command? */
(sed_cmd->end_line
? sed_cmd->end_line == -1
? !next_line
: (sed_cmd->end_line <= linenum)
: !sed_cmd->end_match
)
/* or does this line matches our last address regex */
|| (sed_cmd->end_match && old_matched
&& (regexec(sed_cmd->end_match,
pattern_space, 0, NULL, 0) == 0)
)
);
}
/* Skip blocks of commands we didn't match */
if (sed_cmd->cmd == '{') {
if (sed_cmd->invert ? matched : !matched) {
unsigned nest_cnt = 0;
while (1) {
if (sed_cmd->cmd == '{')
nest_cnt++;
if (sed_cmd->cmd == '}') {
nest_cnt--;
if (nest_cnt == 0)
break;
}
sed_cmd = sed_cmd->next;
if (!sed_cmd)
bb_error_msg_and_die("unterminated {");
}
}
continue;
}
/* Okay, so did this line match? */
if (sed_cmd->invert ? matched : !matched)
continue; /* no */
/* Update last used regex in case a blank substitute BRE is found */
if (sed_cmd->beg_match) {
G.previous_regex_ptr = sed_cmd->beg_match;
}
/* actual sedding */
dbg("pattern_space:'%s' next_line:'%s' cmd:%c",
pattern_space, next_line, sed_cmd->cmd);
switch (sed_cmd->cmd) {
/* Print line number */
case '=':
fprintf(G.nonstdout, "%d\n", linenum);
break;
/* Write the current pattern space up to the first newline */
case 'P':
{
char *tmp = strchr(pattern_space, '\n');
if (tmp) {
*tmp = '\0';
/* TODO: explain why '\n' below */
sed_puts(pattern_space, '\n');
*tmp = '\n';
break;
}
/* Fall Through */
}
/* Write the current pattern space to output */
case 'p':
/* NB: we print this _before_ the last line
* (of current file) is printed. Even if
* that line is nonterminated, we print
* '\n' here (gnu sed does the same) */
sed_puts(pattern_space, '\n');
break;
/* Delete up through first newline */
case 'D':
{
char *tmp = strchr(pattern_space, '\n');
if (tmp) {
overlapping_strcpy(pattern_space, tmp + 1);
goto restart;
}
}
/* discard this line. */
case 'd':
goto discard_line;
/* Substitute with regex */
case 's':
if (!do_subst_command(sed_cmd, &pattern_space))
break;
dbg("do_subst_command succeeded:'%s'", pattern_space);
substituted |= 1;
/* handle p option */
if (sed_cmd->sub_p)
sed_puts(pattern_space, last_gets_char);
/* handle w option */
if (sed_cmd->sw_file)
puts_maybe_newline(
pattern_space, sed_cmd->sw_file,
&sed_cmd->sw_last_char, last_gets_char);
break;
/* Append line to linked list to be printed later */
case 'a':
append(xstrdup(sed_cmd->string));
break;
/* Insert text before this line */
case 'i':
sed_puts(sed_cmd->string, '\n');
break;
/* Cut and paste text (replace) */
case 'c':
/* Only triggers on last line of a matching range. */
if (!sed_cmd->in_match)
sed_puts(sed_cmd->string, '\n');
goto discard_line;
/* Read file, append contents to output */
case 'r':
{
FILE *rfile;
rfile = fopen_for_read(sed_cmd->string);
if (rfile) {
char *line;
while ((line = xmalloc_fgetline(rfile))
!= NULL)
append(line);
fclose(rfile);
}
break;
}
/* Write pattern space to file. */
case 'w':
puts_maybe_newline(
pattern_space, sed_cmd->sw_file,
&sed_cmd->sw_last_char, last_gets_char);
break;
/* Read next line from input */
case 'n':
if (!G.be_quiet)
sed_puts(pattern_space, last_gets_char);
if (next_line) {
free(pattern_space);
pattern_space = next_line;
last_gets_char = next_gets_char;
next_line = get_next_line(&next_gets_char, &last_puts_char, last_gets_char);
substituted = 0;
linenum++;
break;
}
/* fall through */
/* Quit. End of script, end of input. */
case 'q':
/* Exit the outer while loop */
free(next_line);
next_line = NULL;
goto discard_commands;
/* Append the next line to the current line */
case 'N':
{
int len;
/* If no next line, jump to end of script and exit. */
/* http://www.gnu.org/software/sed/manual/sed.html:
* "Most versions of sed exit without printing anything
* when the N command is issued on the last line of
* a file. GNU sed prints pattern space before exiting
* unless of course the -n command switch has been
* specified. This choice is by design."
*/
if (next_line == NULL) {
//goto discard_line;
goto discard_commands; /* GNU behavior */
}
/* Append next_line, read new next_line. */
len = strlen(pattern_space);
pattern_space = xrealloc(pattern_space, len + strlen(next_line) + 2);
pattern_space[len] = '\n';
strcpy(pattern_space + len+1, next_line);
last_gets_char = next_gets_char;
next_line = get_next_line(&next_gets_char, &last_puts_char, last_gets_char);
linenum++;
break;
}
/* Test/branch if substitution occurred */
case 't':
if (!substituted) break;
substituted = 0;
/* Fall through */
/* Test/branch if substitution didn't occur */
case 'T':
if (substituted) break;
/* Fall through */
/* Branch to label */
case 'b':
if (!sed_cmd->string) goto discard_commands;
else sed_cmd = branch_to(sed_cmd->string);
break;
/* Transliterate characters */
case 'y':
{
int i, j;
for (i = 0; pattern_space[i]; i++) {
for (j = 0; sed_cmd->string[j]; j += 2) {
if (pattern_space[i] == sed_cmd->string[j]) {
pattern_space[i] = sed_cmd->string[j + 1];
break;
}
}
}
break;
}
case 'g': /* Replace pattern space with hold space */
free(pattern_space);
pattern_space = xstrdup(G.hold_space ? G.hold_space : "");
break;
case 'G': /* Append newline and hold space to pattern space */
{
int pattern_space_size = 2;
int hold_space_size = 0;
if (pattern_space)
pattern_space_size += strlen(pattern_space);
if (G.hold_space)
hold_space_size = strlen(G.hold_space);
pattern_space = xrealloc(pattern_space,
pattern_space_size + hold_space_size);
if (pattern_space_size == 2)
pattern_space[0] = 0;
strcat(pattern_space, "\n");
if (G.hold_space)
strcat(pattern_space, G.hold_space);
last_gets_char = '\n';
break;
}
case 'h': /* Replace hold space with pattern space */
free(G.hold_space);
G.hold_space = xstrdup(pattern_space);
break;
case 'H': /* Append newline and pattern space to hold space */
{
int hold_space_size = 2;
int pattern_space_size = 0;
if (G.hold_space)
hold_space_size += strlen(G.hold_space);
if (pattern_space)
pattern_space_size = strlen(pattern_space);
G.hold_space = xrealloc(G.hold_space,
hold_space_size + pattern_space_size);
if (hold_space_size == 2)
*G.hold_space = 0;
strcat(G.hold_space, "\n");
if (pattern_space)
strcat(G.hold_space, pattern_space);
break;
}
case 'x': /* Exchange hold and pattern space */
{
char *tmp = pattern_space;
pattern_space = G.hold_space ? G.hold_space : xzalloc(1);
last_gets_char = '\n';
G.hold_space = tmp;
break;
}
} /* switch */
} /* for each cmd */
/*
* Exit point from sedding...
*/
discard_commands:
/* we will print the line unless we were told to be quiet ('-n')
or if the line was suppressed (ala 'd'elete) */
if (!G.be_quiet)
sed_puts(pattern_space, last_gets_char);
/* Delete and such jump here. */
discard_line:
flush_append(&last_puts_char, last_gets_char);
free(pattern_space);
goto again;
}
/* It is possible to have a command line argument with embedded
* newlines. This counts as multiple command lines.
* However, newline can be escaped: 's/e/z\<newline>z/'
* add_cmd() handles this.
*/
static void add_cmd_block(char *cmdstr)
{
char *sv, *eol;
cmdstr = sv = xstrdup(cmdstr);
do {
eol = strchr(cmdstr, '\n');
if (eol)
*eol = '\0';
add_cmd(cmdstr);
cmdstr = eol + 1;
} while (eol);
free(sv);
}
int sed_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int sed_main(int argc UNUSED_PARAM, char **argv)
{
unsigned opt;
llist_t *opt_e, *opt_f;
char *opt_i;
#if ENABLE_LONG_OPTS
static const char sed_longopts[] ALIGN1 =
/* name has_arg short */
"in-place\0" Optional_argument "i"
"regexp-extended\0" No_argument "r"
"quiet\0" No_argument "n"
"silent\0" No_argument "n"
"expression\0" Required_argument "e"
"file\0" Required_argument "f";
#endif
INIT_G();
/* destroy command strings on exit */
if (ENABLE_FEATURE_CLEAN_UP) atexit(sed_free_and_close_stuff);
/* Lie to autoconf when it starts asking stupid questions. */
if (argv[1] && strcmp(argv[1], "--version") == 0) {
puts("This is not GNU sed version 4.0");
return 0;
}
/* do normal option parsing */
opt_e = opt_f = NULL;
opt_i = NULL;
opt_complementary = "e::f::" /* can occur multiple times */
"nn"; /* count -n */
IF_LONG_OPTS(applet_long_options = sed_longopts);
/* -i must be first, to match OPT_in_place definition */
/* -E is a synonym of -r:
* GNU sed 4.2.1 mentions it in neither --help
* nor manpage, but does recognize it.
*/
opt = getopt32(argv, "i::rEne:f:", &opt_i, &opt_e, &opt_f,
&G.be_quiet); /* counter for -n */
//argc -= optind;
argv += optind;
if (opt & OPT_in_place) { // -i
atexit(cleanup_outname);
}
if (opt & (2|4))
G.regex_type |= REG_EXTENDED; // -r or -E
//if (opt & 8)
// G.be_quiet++; // -n (implemented with a counter instead)
while (opt_e) { // -e
add_cmd_block(llist_pop(&opt_e));
}
while (opt_f) { // -f
char *line;
FILE *cmdfile;
cmdfile = xfopen_for_read(llist_pop(&opt_f));
while ((line = xmalloc_fgetline(cmdfile)) != NULL) {
add_cmd(line);
free(line);
}
fclose(cmdfile);
}
/* if we didn't get a pattern from -e or -f, use argv[0] */
if (!(opt & 0x30)) {
if (!*argv)
bb_show_usage();
add_cmd_block(*argv++);
}
/* Flush any unfinished commands. */
add_cmd("");
/* By default, we write to stdout */
G.nonstdout = stdout;
/* argv[0..(argc-1)] should be names of file to process. If no
* files were specified or '-' was specified, take input from stdin.
* Otherwise, we process all the files specified. */
G.input_file_list = argv;
if (!argv[0]) {
if (opt & OPT_in_place)
bb_error_msg_and_die(bb_msg_requires_arg, "-i");
argv[0] = (char*)bb_msg_standard_input;
/* G.last_input_file = 0; - already is */
} else {
goto start;
for (; *argv; argv++) {
struct stat statbuf;
int nonstdoutfd;
sed_cmd_t *sed_cmd;
G.last_input_file++;
start:
if (!(opt & OPT_in_place)) {
if (LONE_DASH(*argv)) {
*argv = (char*)bb_msg_standard_input;
process_files();
}
continue;
}
/* -i: process each FILE separately: */
if (stat(*argv, &statbuf) != 0) {
bb_simple_perror_msg(*argv);
G.exitcode = EXIT_FAILURE;
G.current_input_file++;
continue;
}
G.outname = xasprintf("%sXXXXXX", *argv);
nonstdoutfd = xmkstemp(G.outname);
G.nonstdout = xfdopen_for_write(nonstdoutfd);
/* Set permissions/owner of output file */
/* chmod'ing AFTER chown would preserve suid/sgid bits,
* but GNU sed 4.2.1 does not preserve them either */
fchmod(nonstdoutfd, statbuf.st_mode);
fchown(nonstdoutfd, statbuf.st_uid, statbuf.st_gid);
process_files();
fclose(G.nonstdout);
G.nonstdout = stdout;
if (opt_i) {
char *backupname = xasprintf("%s%s", *argv, opt_i);
xrename(*argv, backupname);
free(backupname);
}
/* else unlink(*argv); - rename below does this */
xrename(G.outname, *argv); //TODO: rollback backup on error?
free(G.outname);
G.outname = NULL;
/* Fix disabled range matches and mangled ",+N" ranges */
for (sed_cmd = G.sed_cmd_head; sed_cmd; sed_cmd = sed_cmd->next) {
sed_cmd->beg_line = sed_cmd->beg_line_orig;
sed_cmd->end_line = sed_cmd->end_line_orig;
}
}
/* Here, to handle "sed 'cmds' nonexistent_file" case we did:
* if (G.current_input_file[G.current_input_file] == NULL)
* return G.exitcode;
* but it's not needed since process_files() works correctly
* in this case too. */
}
process_files();
return G.exitcode;
}