[hackers] [sbase][PATCH] printenv: exit status is 2 on failure

From: Mattias Andrée <maandree_AT_kth.se>
Date: Wed, 30 Mar 2016 01:21:46 +0200

This provides a reliable and portable way to
test whether an environment variable is defined.

(Of course, if you are using glibc you may get
false positives if you include a = in the query.)

Signed-off-by: Mattias Andrée <maandree_AT_kth.se>

---
 printenv.1 | 11 ++++++++++-
 printenv.c |  2 +-
 2 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/printenv.1 b/printenv.1
index a61efe9..dc45c8a 100644
--- a/printenv.1
+++ b/printenv.1
_AT_@ -1,4 +1,4 @@
-.Dd 2015-10-08
+.Dd 2016-03-30
 .Dt PRINTENV 1
 .Os sbase
 .Sh NAME
_AT_@ -16,5 +16,14 @@ is given. Otherwise,
 prints only the value of each
 .Ar var
 one per line in the order specified.
+.SH EXIT STATUS
+.Bl -tag -width Ds
+.It 0
+Successful completion.
+.It 1
+One or more queried variables were not found.
+.It > 1
+An error occurred.
+.El
 .Sh SEE ALSO
 .Xr env 1
diff --git a/printenv.c b/printenv.c
index 2c1e711..2e1d15b 100644
--- a/printenv.c
+++ b/printenv.c
_AT_@ -26,5 +26,5 @@ main(int argc, char *argv[])
 		}
 	}
 
-	return fshut(stdout, "<stdout>") || ret;
+	return fshut(stdout, "<stdout>") ? 2 : ret;
 }
-- 
2.7.4

Received on Wed Mar 30 2016 - 01:21:46 CEST