sed -i handling (illumos)

01_sed.diff

diff --git a/usr/src/cmd/sed/main.c b/usr/src/cmd/sed/main.c
index 93e14bb..3a3f805 100644
--- a/usr/src/cmd/sed/main.c
+++ b/usr/src/cmd/sed/main.c
@@ -120,7 +120,7 @@ static char *getln(FILE *, size_t *);
 int
 main(int argc, char *argv[])
 {
-       int c, fflag;
+       int i, j, c, fflag;
        char *temp_arg;
 
        (void) setlocale(LC_ALL, "");
@@ -133,6 +133,23 @@ main(int argc, char *argv[])
        fflag = 0;
        inplace = NULL;
 
+        /*
+        * Coalesce |-i ''| into |-i| so that we're compatible with earlier
+        * illumos sed, whilst remaining compatible with GNU sed by using 
+        * getopt_long.
+        */
+       for (i = 2; i < argc; i++) {
+               if (strcmp("-i", argv[i - 1]) == 0 && argv[i][0] == '\0') {
+                       /* We have:  -i '' */
+                       for (j = i; j < argc - 1; j++) {
+                               /* move the arguments back by one */
+                               argv[j] = argv[j + 1];
+                       }
+                       argv[j] = (char *)NULL;
+                       argc--;
+               }
+       }
+
        while ((c = getopt_long(argc, argv, "EI::ae:f:i::lnr", lopts, NULL)) !=
            -1)
                switch (c) {

02_output.txt

leftwing@onbld0 tmp $ cc -o tt test.c && ./tt '' -i -i 'awesome' some number -i '' of arguments -i ''
8047b45 -> ''
8047b46 -> '-i'
8047b49 -> '-i'
8047b4c -> 'awesome'
8047b54 -> 'some'
8047b59 -> 'number'
8047b60 -> '-i'
8047b64 -> 'of'
8047b67 -> 'arguments'
8047b71 -> '-i'
0 -> '(null)'
leftwing@onbld0 tmp $ ./tt 
0 -> '(null)'
leftwing@onbld0 tmp $ ./tt -i -i
8047b71 -> '-i'
8047b74 -> '-i'
0 -> '(null)'
leftwing@onbld0 tmp $ ./tt -i -i '' -i -i roger -i
8047b61 -> '-i'
8047b64 -> '-i'
8047b68 -> '-i'
8047b6b -> '-i'
8047b6e -> 'roger'
8047b74 -> '-i'
0 -> '(null)'
leftwing@onbld0 tmp $ ./tt -i -i '' -i -i roger -i -j ''
8047b5d -> '-i'
8047b60 -> '-i'
8047b64 -> '-i'
8047b67 -> '-i'
8047b6a -> 'roger'
8047b70 -> '-i'
8047b73 -> '-j'
8047b76 -> ''
0 -> '(null)'

03_test.c

#include <stdlib.h>
#include <stdio.h>
#include <strings.h>

int
main(int argc, char *argv[])
{
        int i, j;

        /* coalesce |-i ''| into |-i| ... */
        for (i = 2; i < argc; i++) {
                if (strcmp("-i", argv[i - 1]) == 0 && argv[i][0] == '\0') {
                        /* We have:  -i '' */
                        for (j = i; j < argc - 1; j++) {
                                /* move arguments back by one */
                                argv[j] = argv[j + 1];
                        }
                        argv[j] = (char *)NULL;
                        argc--;
                }
        }

        /* print the args */
        for (i = 1; i <= argc; i++) {
                printf("%p -> '%s'\n", argv[i], argv[i]);
        }
}