Quote bash variables and ensure file existence

Ensure filenames with spaces don't make the sample script choke

1 files changed, 12 insertions, 8 deletions

diff --git a/_posts/2009-09-03-working-with-key-passphrases.textile b/_posts/2009-09-03-working-with-key-passphrases.textile
index 988e66b..c168c84 100644
--- a/_posts/2009-09-03-working-with-key-passphrases.textile
+++ b/_posts/2009-09-03-working-with-key-passphrases.textile
@@ -42,10 +42,10 @@ SSH_ENV="$HOME/.ssh/environment"
 function start_agent {
     echo "Initializing new SSH agent..."
     # spawn ssh-agent
-    ssh-agent | sed 's/^echo/#echo/' > $SSH_ENV
+    ssh-agent | sed 's/^echo/#echo/' > "$SSH_ENV"
     echo succeeded
-    chmod 600 $SSH_ENV
-    . $SSH_ENV > /dev/null
+    chmod 600 "$SSH_ENV"
+    . "$SSH_ENV" > /dev/null
     ssh-add
 }
 
@@ -63,14 +63,18 @@ function test_identities {
 }
 
 # check for running ssh-agent with proper $SSH_AGENT_PID
-ps -ef | grep $SSH_AGENT_PID | grep ssh-agent > /dev/null
-if [ $? -eq 0 ]; then
-    test_identities
+if [ -n "$SSH_AGENT_PID" ]; then
+    ps -ef | grep "$SSH_AGENT_PID" | grep ssh-agent > /dev/null
+    if [ $? -eq 0 ]; then
+	test_identities
+    fi
 # if $SSH_AGENT_PID is not properly set, we might be able to load one from
 # $SSH_ENV
 else
-    . $SSH_ENV > /dev/null
-    ps -ef | grep $SSH_AGENT_PID | grep ssh-agent > /dev/null
+    if [ -f "$SSH_ENV" ]; then
+	. "$SSH_ENV" > /dev/null
+    fi
+    ps -ef | grep "$SSH_AGENT_PID" | grep ssh-agent > /dev/null
     if [ $? -eq 0 ]; then
         test_identities
     else