sed: improve handling of NULs

This commit is contained in:
Denis Vlasenko 2006-12-02 17:58:10 +00:00
parent becd8c538c
commit 8b22b07bc5
2 changed files with 68 additions and 50 deletions

View File

@ -80,8 +80,8 @@ typedef struct sed_cmd_s {
/* Bitfields (gcc won't group them if we don't) */
unsigned int invert:1; /* the '!' after the address */
unsigned int in_match:1; /* Next line also included in match? */
unsigned int no_newline:1; /* Last line written by (sw) had no '\n' */
unsigned int sub_p:1; /* (s) print option */
int last_char; /* Last line written by (sw) had no '\n' */
/* GENERAL FIELDS */
char cmd; /* The command char: abcdDgGhHilnNpPqrstwxy:={} */
@ -712,56 +712,73 @@ static void add_input_file(FILE *file)
/* Get next line of input from bbg.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(int *no_newline)
static char *get_next_line(int *last_char)
{
char *temp = NULL;
int len;
/* will be returned if last line in the file
* doesn't end with either '\n' or '\0' */
*last_char = 0x100;
flush_append();
while (bbg.current_input_file < bbg.input_file_count) {
temp = bb_get_chunk_from_file(bbg.input_file_list[bbg.current_input_file],&len);
temp = bb_get_chunk_from_file(
bbg.input_file_list[bbg.current_input_file], &len);
if (temp) {
*no_newline = !(len && temp[len-1] == '\n');
if (!*no_newline) temp[len-1] = 0;
/* 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';
*last_char = (unsigned char)c;
}
break;
// Close this file and advance to next one
} else
fclose(bbg.input_file_list[bbg.current_input_file++]);
}
/* Close this file and advance to next one */
fclose(bbg.input_file_list[bbg.current_input_file++]);
}
return temp;
}
/* Output line of text. missing_newline means the last line output did not
end with a newline. no_newline means this line does not end with a
newline. */
/* Output line of text. */
/* Note:
* 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|
* I am not sure that bbox is wrong here...
*/
static int puts_maybe_newline(char *s, FILE *file, int missing_newline, int no_newline)
static int puts_maybe_newline(char *s, FILE *file, int prev_last_char, int last_char)
{
if (missing_newline) fputc('\n',file);
fputs(s,file);
if (!no_newline) fputc('\n',file);
fputs(s, file);
if (last_char < 0x100) fputc(last_char, file);
if (ferror(file)) {
xfunc_error_retval = 4; /* It's what gnu sed exits with... */
bb_error_msg_and_die(bb_msg_write_error);
}
return no_newline;
return last_char;
}
#define sed_puts(s,n) missing_newline=puts_maybe_newline(s,bbg.nonstdout,missing_newline,n)
#define sed_puts(s, n) \
(prev_last_char = puts_maybe_newline(s, bbg.nonstdout, prev_last_char, n))
/* Process all the lines in all the files */
static void process_files(void)
{
char *pattern_space, *next_line;
int linenum = 0, missing_newline = 0;
int no_newline,next_no_newline = 0;
int linenum = 0, prev_last_char = 0;
int last_char, next_last_char = 0;
/* Prime the pump */
next_line = get_next_line(&next_no_newline);
next_line = get_next_line(&next_last_char);
/* go through every line in each file */
for (;;) {
@ -771,11 +788,11 @@ static void process_files(void)
/* Advance to next line. Stop if out of lines. */
pattern_space = next_line;
if (!pattern_space) break;
no_newline = next_no_newline;
last_char = next_last_char;
/* Read one line in advance so we can act on the last line,
* the '$' address */
next_line = get_next_line(&next_no_newline);
next_line = get_next_line(&next_last_char);
linenum++;
restart:
/* for every line, go through all the commands */
@ -858,7 +875,7 @@ restart:
/* Write the current pattern space to output */
case 'p':
sed_puts(pattern_space,no_newline);
sed_puts(pattern_space, last_char);
break;
/* Delete up through first newline */
case 'D':
@ -878,25 +895,24 @@ restart:
/* Substitute with regex */
case 's':
if (do_subst_command(sed_cmd, &pattern_space)) {
substituted |= 1;
if (!do_subst_command(sed_cmd, &pattern_space))
break;
substituted |= 1;
/* handle p option */
if (sed_cmd->sub_p)
sed_puts(pattern_space,no_newline);
/* handle w option */
if (sed_cmd->file)
sed_cmd->no_newline = puts_maybe_newline(pattern_space, sed_cmd->file, sed_cmd->no_newline, no_newline);
}
/* handle p option */
if (sed_cmd->sub_p)
sed_puts(pattern_space, last_char);
/* handle w option */
if (sed_cmd->file)
sed_cmd->last_char = puts_maybe_newline(
pattern_space, sed_cmd->file,
sed_cmd->last_char, last_char);
break;
/* Append line to linked list to be printed later */
case 'a':
{
append(sed_cmd->string);
break;
}
/* Insert text before this line */
case 'i':
@ -930,18 +946,20 @@ restart:
/* Write pattern space to file. */
case 'w':
sed_cmd->no_newline = puts_maybe_newline(pattern_space,sed_cmd->file, sed_cmd->no_newline,no_newline);
sed_cmd->last_char = puts_maybe_newline(
pattern_space,sed_cmd->file,
sed_cmd->last_char, last_char);
break;
/* Read next line from input */
case 'n':
if (!bbg.be_quiet)
sed_puts(pattern_space,no_newline);
sed_puts(pattern_space, last_char);
if (next_line) {
free(pattern_space);
pattern_space = next_line;
no_newline = next_no_newline;
next_line = get_next_line(&next_no_newline);
last_char = next_last_char;
next_line = get_next_line(&next_last_char);
linenum++;
break;
}
@ -970,8 +988,8 @@ restart:
pattern_space = realloc(pattern_space, len + strlen(next_line) + 2);
pattern_space[len] = '\n';
strcpy(pattern_space + len+1, next_line);
no_newline = next_no_newline;
next_line = get_next_line(&next_no_newline);
last_char = next_last_char;
next_line = get_next_line(&next_last_char);
linenum++;
}
break;
@ -1029,7 +1047,7 @@ restart:
strcat(pattern_space, "\n");
if (bbg.hold_space)
strcat(pattern_space, bbg.hold_space);
no_newline = 0;
last_char = 0x100;
break;
}
@ -1061,7 +1079,7 @@ restart:
{
char *tmp = pattern_space;
pattern_space = bbg.hold_space ? : xzalloc(1);
no_newline = 0;
last_char = 0x100;
bbg.hold_space = tmp;
break;
}
@ -1075,7 +1093,7 @@ restart:
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 (!bbg.be_quiet) sed_puts(pattern_space,no_newline);
if (!bbg.be_quiet) sed_puts(pattern_space, last_char);
/* Delete and such jump here. */
discard_line:

View File

@ -11,8 +11,8 @@
#include "libbb.h"
/* This function reads an entire line from a text file,
* up to a newline or NUL byte. It returns a malloc'ed char * which must be
/* This function reads an entire line from a text file, up to a newline
* or NUL byte, inclusive. It returns a malloc'ed char * which must be
* stored and free'ed by the caller. If end is null '\n' isn't considered
* end of line. If end isn't null, length of the chunk read is stored in it. */
@ -25,7 +25,7 @@ char *bb_get_chunk_from_file(FILE * file, int *end)
while ((ch = getc(file)) != EOF) {
/* grow the line buffer as necessary */
if (idx > linebufsz - 2) {
if (idx >= linebufsz) {
linebuf = xrealloc(linebuf, linebufsz += 80);
}
linebuf[idx++] = (char) ch;
@ -35,14 +35,14 @@ char *bb_get_chunk_from_file(FILE * file, int *end)
if (end)
*end = idx;
if (linebuf) {
// huh, is fgets discards prior data on error like this?
// huh, does fgets discard prior data on error like this?
// I don't think so....
//if (ferror(file)) {
// free(linebuf);
// return NULL;
//}
linebuf = xrealloc(linebuf, idx+1);
linebuf[idx] = 0;
linebuf[idx] = '\0';
}
return linebuf;
}