1 files changed, 38 insertions, 0 deletions
diff --git a/src/libstddjb/execvep.c b/src/libstddjb/execvep.c
new file mode 100644
index 0000000..1639236
--- /dev/null
+++ b/src/libstddjb/execvep.c
@@ -0,0 +1,38 @@
+/* ISC license. */
+
+#include <unistd.h>
+#include <errno.h>
+#include <skalibs/bytestr.h>
+#include <skalibs/djbunix.h>
+
+void execvep (char const *file, char const *const *argv, char const *const *envp, char const *path)
+{
+  if (!path) errno = EINVAL ;
+  else if (file[str_chr(file, '/')])
+    execve(file, (char *const *)argv, (char *const *)envp) ; /* execve prototype sucks */
+  else
+  {
+    unsigned int pathlen = str_len(path) + 1 ;
+    unsigned int filelen = str_len(file) ;
+    int savederrno = 0 ;
+    while (pathlen)
+    {
+      unsigned int split = byte_chr(path, pathlen - 1, ':') ;
+      if (split)
+      {
+        char tmp[split + 2 + filelen] ;
+        byte_copy(tmp, split, path) ;
+        tmp[split] = '/' ;
+        byte_copy(tmp + split + 1, filelen + 1, file) ;
+        execve(tmp, (char *const *)argv, (char *const *)envp) ;
+        if (errno != ENOENT)
+        {
+          savederrno = errno ;
+          if ((errno != EACCES) && (errno != EPERM) && (errno != EISDIR)) break ;
+        }
+      }
+      path += split+1 ; pathlen -= split+1 ;
+    }
+    if (savederrno) errno = savederrno ;
+  }
+}