Re: [patch] usr.bin/mg/region.c: Set default shell path if SHELL is NULL

[Omar Polo]

On 2023/03/28 10:21:59 +0200, Omar Polo <o...@omarpolo.com> wrote:
> On 2023/03/27 18:58:07 -0600, Todd C. Miller <mill...@openbsd.org> wrote:
> > It might be best to use the basename of the actual shell for argv[0].
> > Our ksh for instance has slightly different behavior when invoked
> > as sh.
> 
> like this? :)
> 
> (need an up-to-date tree since it builds on the previous, committed,
> diff.)
> 
> I've tested with ksh and csh.  I guess it's fine to assume the user'
> shell has a -c flag.  (vi does the same.)
> 
> 
> Thanks!

sigh... forgot to advance the pointer after strrchr otherwise argv[0]
would have been /ksh instead of "ksh".

Index: region.c
===================================================================
RCS file: /cvs/src/usr.bin/mg/region.c,v
retrieving revision 1.43
diff -u -p -r1.43 region.c
--- region.c    28 Mar 2023 08:01:40 -0000      1.43
+++ region.c    28 Mar 2023 14:13:26 -0000
@@ -34,7 +34,7 @@ static        int     iomux(int, char * const, int,
 static int     preadin(int, struct buffer *);
 static void    pwriteout(int, char **, int *);
 static int     setsize(struct region *, RSIZE);
-static int     shellcmdoutput(char * const[], char * const, int);
+static int     shellcmdoutput(char * const, char * const, int);
 
 /*
  * Kill the region.  Ask "getregion" to figure out the bounds of the region.
@@ -415,7 +415,6 @@ piperegion(int f, int n)
        struct region region;
        int len;
        char *cmd, cmdbuf[NFILEN], *text;
-       char *argv[] = {"sh", "-c", (char *) NULL, (char *) NULL};
 
        /* C-u M-| is not supported yet */
        if (n > 1)
@@ -431,8 +430,6 @@ piperegion(int f, int n)
            EFNEW | EFCR)) == NULL || (cmd[0] == '\0'))
                return (ABORT);
 
-       argv[2] = cmd;
-
        if (getregion(&region) != TRUE)
                return (FALSE);
 
@@ -446,7 +443,7 @@ piperegion(int f, int n)
 
        region_get_data(&region, text, len);
 
-       return shellcmdoutput(argv, text, len);
+       return shellcmdoutput(cmd, text, len);
 }
 
 /*
@@ -456,7 +453,6 @@ int
 shellcommand(int f, int n)
 {
        char *cmd, cmdbuf[NFILEN];
-       char *argv[] = {"sh", "-c", (char *) NULL, (char *) NULL};
 
        if (n > 1)
                return (ABORT);
@@ -465,15 +461,14 @@ shellcommand(int f, int n)
            EFNEW | EFCR)) == NULL || (cmd[0] == '\0'))
                return (ABORT);
 
-       argv[2] = cmd;
-
-       return shellcmdoutput(argv, NULL, 0);
+       return shellcmdoutput(cmd, NULL, 0);
 }
 
 int
-shellcmdoutput(char* const argv[], char* const text, int len)
+shellcmdoutput(char* const cmd, char* const text, int len)
 {
        struct buffer *bp;
+       char    *argv[] = {NULL, "-c", cmd, NULL};
        char    *shellp;
        int      ret;
 
@@ -486,6 +481,11 @@ shellcmdoutput(char* const argv[], char*
 
        if ((shellp = getenv("SHELL")) == NULL)
                shellp = _PATH_BSHELL;
+
+       if ((argv[0] = strrchr(shellp, '/')) != NULL)
+               argv[0]++;
+       else
+               argv[0] = shellp;
 
        ret = pipeio(shellp, argv, text, len, bp);