sed: implement ",+N" range end

function                                             old     new   delta
add_cmd                                             1115    1173     +58
process_files                                       2226    2253     +27
sed_main                                             696     702      +6
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/0 up/down: 91/0)               Total: 91 bytes

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

2 files changed, 68 insertions, 5 deletions

diff --git a/editors/sed.c b/editors/sed.c
index 2c64ad500..7bbf820d8 100644
--- a/editors/sed.c
+++ b/editors/sed.c
@@ -53,6 +53,7 @@
  * 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
@@ -109,7 +110,8 @@ typedef struct sed_cmd_s {
         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 ($) */
+        int end_line;           /* 'sed 1,3p' 0 == one line only. -1 = last line ($). -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. */
@@ -640,10 +642,29 @@ static void add_cmd(const char *cmdstr)
                         int idx;
 
                         cmdstr++;
-                        idx = get_address(cmdstr, &sed_cmd->end_line, &sed_cmd->end_match);
-                        if (!idx)
+                        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");
-                        cmdstr += idx;
+                        sed_cmd->end_line_orig = sed_cmd->end_line;
                 }
 
                 /* skip whitespace before the command */
@@ -1089,10 +1110,19 @@ static void process_files(void)
                 /* 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
@@ -1551,9 +1581,10 @@ int sed_main(int argc UNUSED_PARAM, char **argv)
                         free(G.outname);
                         G.outname = NULL;
 
-                        /* Re-enable disabled range matches */
+                        /* 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:
diff --git a/testsuite/sed.tests b/testsuite/sed.tests
index 19f2915ce..34479e55f 100755
--- a/testsuite/sed.tests
+++ b/testsuite/sed.tests
@@ -333,6 +333,38 @@ testing "sed s///NUM test" \
         "sed -e 's/a/b/2; s/a/c/g'" \
         "cb\n" "" "aa\n"
 
+testing "sed /regex/,N{...} addresses work" \
+        "sed /^2/,2{d}" \
+        "1\n3\n4\n5\n" \
+        "" \
+        "1\n2\n3\n4\n5\n"
+
+testing "sed /regex/,+N{...} addresses work" \
+        "sed /^2/,+2{d}" \
+        "1\n5\n" \
+        "" \
+        "1\n2\n3\n4\n5\n"
+
+testing "sed /regex/,+N{...} -i works" \
+        "cat - >input2; sed /^4/,+2{d} -i input input2; echo \$?; cat input input2; rm input2" \
+        "0\n""1\n2\n3\n7\n8\n""1\n2\n7\n8\n" \
+        "1\n2\n3\n4\n5\n6\n7\n8\n" \
+        "1\n2\n4\n5\n6\n7\n8\n" \
+
+# GNU sed 4.2.1 would also accept "/^4/,+{d}" with the same meaning, we don't
+testing "sed /regex/,+0{...} -i works" \
+        "cat - >input2; sed /^4/,+0{d} -i input input2; echo \$?; cat input input2; rm input2" \
+        "0\n""1\n2\n3\n5\n6\n7\n8\n""1\n2\n5\n6\n7\n8\n" \
+        "1\n2\n3\n4\n5\n6\n7\n8\n" \
+        "1\n2\n4\n5\n6\n7\n8\n" \
+
+# GNU sed 4.2.1 would also accept "/^4/,+d" with the same meaning, we don't
+testing "sed /regex/,+0<cmd> -i works" \
+        "cat - >input2; sed /^4/,+0d -i input input2; echo \$?; cat input input2; rm input2" \
+        "0\n""1\n2\n3\n5\n6\n7\n8\n""1\n2\n5\n6\n7\n8\n" \
+        "1\n2\n3\n4\n5\n6\n7\n8\n" \
+        "1\n2\n4\n5\n6\n7\n8\n" \
+
 # testing "description" "commands" "result" "infile" "stdin"
 
 exit $FAILCOUNT