sed: improve handling of NULs

diff --git a/editors/sed.c b/editors/sed.c
index a1602394523f73dd3b88757a5bba157d982cd7a4..630d6d792ecd34d51a1d2915c924f734e1e0d120 100644 (file)
--- a/editors/sed.c
+++ b/editors/sed.c
@@ -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;
-
-                                               /* 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);
-
-                                       }
+                                       if (!do_subst_command(sed_cmd, &pattern_space))
+                                               break;
+                                       substituted |= 1;
+
+                                       /* 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:

diff --git a/libbb/get_line_from_file.c b/libbb/get_line_from_file.c
index b424d59e913ade059c0434d85c12c545289b6311..3f2c6096eefde5ce4d42b2ca244e4a1715c16415 100644 (file)
--- a/libbb/get_line_from_file.c
+++ b/libbb/get_line_from_file.c
@@ -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;
 }