[hackers] [sbase] which: Move executable check to helper function || Michael Forney

[git]

commit 44265b29ce2da27a525c72e3e9b48f3233535ec1
Author:     Michael Forney <mfor...@mforney.org>
AuthorDate: Fri Oct 20 12:30:20 2017 -0700
Commit:     Michael Forney <mfor...@mforney.org>
CommitDate: Sat Oct 21 12:44:09 2017 -0700

    which: Move executable check to helper function

diff --git a/which.c b/which.c
index dfc1551..e47aa63 100644
--- a/which.c
+++ b/which.c
@@ -14,17 +14,24 @@
 static int aflag;
 
 static int
+canexec(int fd, const char *name)
+{
+       struct stat st;
+
+       if (fstatat(fd, name, &st, 0) < 0 || !S_ISREG(st.st_mode))
+               return 0;
+       return faccessat(fd, name, X_OK, 0) == 0;
+}
+
+static int
 which(const char *path, const char *name)
 {
        char *ptr, *p;
        size_t i, len;
-       struct stat st;
        int dirfd, found = 0;
 
        if (strchr(name, '/')) {
-               if (!fstatat(AT_FDCWD, name, &st, 0) &&
-                   S_ISREG(st.st_mode) &&
-                   !access(name, X_OK)) {
+               if (canexec(AT_FDCWD, name)) {
                        puts(name);
                        return 1;
                }
@@ -37,9 +44,7 @@ which(const char *path, const char *name)
                        continue;
                ptr[i] = '\0';
                if ((dirfd = open(p, O_RDONLY, 0)) >= 0) {
-                       if (!fstatat(dirfd, name, &st, 0) &&
-                           S_ISREG(st.st_mode) &&
-                           !faccessat(dirfd, name, X_OK, 0)) {
+                       if (canexec(dirfd, name)) {
                                found = 1;
                                fputs(p, stdout);
                                if (i && ptr[i - 1] != '/')