sed: understand \n,\r and \t in i and a commands. Closes 8871

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/editors/sed.c b/editors/sed.c
index 6bce25b2cfd6a6c4ccda6ba54a161ad90ee265df..7f18fd0c4d42a5ebbefdbc607cdddad0b1707773 100644 (file)
--- a/editors/sed.c
+++ b/editors/sed.c
@@ -218,23 +218,33 @@ static void cleanup_outname(void)
 
 /* 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)
+static unsigned parse_escapes(char *dest, const char *string, int len, char from, char to)
 {
+       char *d = dest;
        int i = 0;
 
+       if (len == -1)
+               len = strlen(string);
+
        while (i < len) {
                if (string[i] == '\\') {
                        if (!to || string[i+1] == from) {
-                               *dest++ = to ? to : string[i+1];
+                               if ((*d = to ? to : string[i+1]) == '\0')
+                                       return d - dest;
                                i += 2;
+                               d++;
                                continue;
                        }
-                       *dest++ = string[i++];
+                       i++; /* skip backslash in string[] */
+                       *d++ = '\\';
+                       /* fall through: copy next char verbatim */
                }
-               /* TODO: is it safe wrt a string with trailing '\\' ? */
-               *dest++ = string[i++];
+               if ((*d = string[i++]) == '\0')
+                       return d - dest;
+               d++;
        }
-       *dest = '\0';
+       *d = '\0';
+       return d - dest;
 }
 
 static char *copy_parsing_escapes(const char *string, int len)
@@ -245,9 +255,8 @@ static char *copy_parsing_escapes(const char *string, int len)
        /* 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]);
+               len = parse_escapes(dest, string, len, s[1], s[0]);
                string = dest;
-               len = strlen(dest);
        }
        return dest;
 }
@@ -516,6 +525,8 @@ static const char *parse_cmd_args(sed_cmd_t *sed_cmd, const char *cmdstr)
        }
        /* handle edit cmds: (a)ppend, (i)nsert, and (c)hange */
        else if (idx <= IDX_c) { /* a,i,c */
+               unsigned len;
+
                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);
@@ -529,10 +540,11 @@ static const char *parse_cmd_args(sed_cmd_t *sed_cmd, const char *cmdstr)
                                break;
                        cmdstr++;
                }
-               sed_cmd->string = xstrdup(cmdstr);
+               len = strlen(cmdstr);
+               sed_cmd->string = copy_parsing_escapes(cmdstr, len);
+               cmdstr += len;
                /* "\anychar" -> "anychar" */
-               parse_escapes(sed_cmd->string, sed_cmd->string, strlen(cmdstr), '\0', '\0');
-               cmdstr += strlen(cmdstr);
+               parse_escapes(sed_cmd->string, sed_cmd->string, -1, '\0', '\0');
        }
        /* handle file cmds: (r)ead */
        else if (idx <= IDX_w) { /* r,w */
@@ -564,8 +576,8 @@ static const char *parse_cmd_args(sed_cmd_t *sed_cmd, const char *cmdstr)
 
                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);
+               parse_escapes(match,   match,   -1, i, i);
+               parse_escapes(replace, replace, -1, i, i);
 
                sed_cmd->string = xzalloc((strlen(match) + 1) * 2);
                for (i = 0; match[i] && replace[i]; i++) {

diff --git a/testsuite/sed.tests b/testsuite/sed.tests
index 5d2356b641445b01dc02dab2d7f4c072d67ef46a..c4b6fa278fbc4d141ba382047c261c0f588e1332 100755 (executable)
--- a/testsuite/sed.tests
+++ b/testsuite/sed.tests
@@ -275,6 +275,24 @@ testing "sed a cmd ended by double backslash" \
        | two \\
 '
 
+testing "sed a cmd understands \\n,\\t,\\r" \
+       "sed '/1/a\\\\t\\rzero\\none\\\\ntwo\\\\\\nthree'" \
+"\
+line1
+\t\rzero
+one\\\\ntwo\\
+three
+" "" "line1\n"
+
+testing "sed i cmd understands \\n,\\t,\\r" \
+       "sed '/1/i\\\\t\\rzero\\none\\\\ntwo\\\\\\nthree'" \
+"\
+\t\rzero
+one\\\\ntwo\\
+three
+line1
+" "" "line1\n"
+
 # first three lines are deleted; 4th line is matched and printed by "2,3" and by "4" ranges
 testing "sed with N skipping lines past ranges on next cmds" \
        "sed -n '1{N;N;d};1p;2,3p;3p;4p'" \