Support umask function.

* sysif.c (umask_wrap): New function.
(sysif_init): Register umask intrinsic.

* txr.1: Documented.

2 files changed, 30 insertions, 0 deletions

diff --git a/sysif.c b/sysif.c
index 7b072072..dd5f2409 100644
--- a/sysif.c
+++ b/sysif.c
@@ -668,6 +668,16 @@ val statf(val stream)
   return stat_impl(stream, w_fstat, lit("fstat"));
 }
 
+#if HAVE_SYS_STAT
+
+static val umask_wrap(val mask)
+{
+  (void) umask(c_num(mask));
+  return t;
+}
+
+#endif
+
 #if HAVE_PIPE
 
 static val pipe_wrap(void)
@@ -1475,4 +1485,8 @@ void sysif_init(void)
 #if HAVE_POLL
   reg_fun(intern(lit("poll"), user_package), func_n2o(poll_wrap, 1));
 #endif
+
+#if HAVE_SYS_STAT
+  reg_fun(intern(lit("umask"), user_package), func_n1(umask_wrap));
+#endif
 }
diff --git a/txr.1 b/txr.1
index 569864b8..63c2938b 100644
--- a/txr.1
+++ b/txr.1
@@ -35712,6 +35712,22 @@ For example
 .code (logtest mode s-irgrp)
 tests for the group read permission.
 
+.coNP Functions @ umask
+.synb
+.mets (umask << mask )
+.syne
+.desc
+The
+.code umask
+function provides access to the Unix C library function of the same name,
+which controls which permissions are denied
+when files are newly created. If
+.meta mask
+is a
+.code fixnum
+integer, this succeeds and returns
+.codn t .
+
 .coNP Functions @, makedev @ minor and @ major
 .synb
 .mets (makedev < minor << major )