Add isgr(1)

3 files changed, 28 insertions, 0 deletions

diff --git a/README.markdown b/README.markdown
index 52a2d4b0..2cdafdb3 100644
--- a/README.markdown
+++ b/README.markdown
@@ -328,6 +328,8 @@ Installed by the `install-bin` target:
     look for `help` topics. You could use it from the shell too.
 *   `igex(1)` wraps around a command to allow you to ignore error conditions
     that don't actually worry you, exiting with 0 anyway.
+*   `isgr(1)` quietly tests whether the given directory appears to be a Git
+    repository
 *   `jfc(1)` adds and commits lazily to a Git repository.
 *   `jfcd(1)` watches a directory for changes and runs `jfc(1)` if it sees any.
 *   `maybe(1)` is like `true(1)` or `false(1)`; given a probability of success,
diff --git a/bin/isgr b/bin/isgr
new file mode 100755
index 00000000..9cb37c1a
--- /dev/null
+++ b/bin/isgr
@@ -0,0 +1,8 @@
+#!/bin/sh
+# Return an exit status for whether the current directory appears to be in a
+# Git working copy
+exec >/dev/null 2>&1
+cd -- "${1:-.}" || exit
+git symbolic-ref --quiet HEAD ||
+git rev-parse --short HEAD ||
+exit 1
diff --git a/man/man1/isgr.1 b/man/man1/isgr.1
new file mode 100644
index 00000000..f997d17a
--- /dev/null
+++ b/man/man1/isgr.1
@@ -0,0 +1,18 @@
+.TH ISGR 1 "August 2016" "Manual page for isgr"
+.SH NAME
+.B isgr
+\- print a count of entries in a directory
+.SH SYNOPSIS
+.B isgr
+.br
+.B isgr
+/path/to/dir
+.SH DESCRIPTION
+.B isgr
+exits with 0 if the given directory (or the current directory if one is not
+given) appears to be a working copy of a Git repository. It exits 1 otherwise.
+All output from the git(1) commands used to check this is suppressed.
+.SH SEE ALSO
+git(1), gscr(1), fgscr(1)
+.SH AUTHOR
+Tom Ryder <tom@sanctum.geek.nz>