1 files changed, 44 insertions, 0 deletions
diff --git a/src/libexecline/el_popenv.c b/src/libexecline/el_popenv.c
new file mode 100644
index 0000000..3726506
--- /dev/null
+++ b/src/libexecline/el_popenv.c
@@ -0,0 +1,44 @@
+/* ISC license. */
+
+#include <errno.h>
+#include <skalibs/bytestr.h>
+#include <skalibs/stralloc.h>
+#include <skalibs/uint.h>
+#include <execline/execline.h>
+
+int el_popenv (stralloc *sa, char const *const *envp, unsigned int envlen, char const *const *list, unsigned int listlen)
+{
+  unsigned int i = 0, salen = sa->len, count = 0 ;
+  for (; i < envlen ; i++)
+  {
+    unsigned int equal, colon, n ;
+    unsigned int j = 0 ;
+    for (; j < listlen ; j++) if (str_start(envp[i], list[j])) break ;
+    if (j == listlen) goto copyit ;
+    j = str_len(list[j]) ;
+    colon = j + str_chr(envp[i] + j, ':') ;
+    equal = j + str_chr(envp[i] + j, '=') ;
+    if (!envp[i][equal]) goto badenv ;
+    if (colon >= equal) { count++ ; continue ; }
+    if (colon + 1 + uint_scan(envp[i] + colon + 1, &n) != equal) goto copyit ;
+    if (!n) goto copyit ;
+    if (!stralloc_catb(sa, envp[i], colon)) goto err ;
+    if (n > 1)
+    {
+      char fmt[UINT_FMT+1] = ":" ;
+      n = 1 + uint_fmt(fmt+1, n-1) ;
+      if (!stralloc_catb(sa, fmt, n)) goto err ;
+    }
+    if (!stralloc_catb(sa, envp[i] + equal, str_len(envp[i] + equal) + 1)) goto err ;
+    continue ;
+copyit:
+    if (!stralloc_catb(sa, envp[i], str_len(envp[i]) + 1)) goto err ;
+  }
+  return (int)count ;
+
+badenv :
+  errno = EINVAL ;
+err:
+  sa->len = salen ;
+  return -1 ;
+}