fix edge case of empty string argument

diff --git a/appendu b/appendu
index c18830da8662a9a22972cdf9f8cae13b0aebaaac..feb58d4ee5b283902f189088d2cae823eeaaf556 100755 (executable)
--- a/appendu
+++ b/appendu
@@ -15,7 +15,7 @@ as a single LINE_SET. Appended text is output to the terminal.
   --      stop processing arguments
   --help  display this message"
 
-    local readsudo writesudo x strings string
+    local readsudo writesudo x strings string content
     local dosudo=true
     
     while true; do
@@ -42,11 +42,10 @@ as a single LINE_SET. Appended text is output to the terminal.
     local file="$1"
     shift
 
-    local readsudo=false
     local file_exists=false
     if [[ -e $file ]]; then
         file_exists=true
-        [[ -r $file ]] || readsudo=true
+        [[ -r $file ]] || readsudo=sudo
         [[ -w $file ]] || writesudo=sudo
     else
         local dir="$(dirname "$file")"
@@ -78,16 +77,10 @@ as a single LINE_SET. Appended text is output to the terminal.
         # so sed only does what it always does when it was supposed to modify a file,
         # which is append a newline if there was none.
         sed -ie '$a\' "$file"
-        # this removes any trailing newline in the var, so we add it back on,
-        # because we want a consistent ending to match
-        local file_content
-        if $readsudo; then
-            file_content="$(sudo cat "$file")
-"
-        else
-            file_content="$(<"$file")
-"
-        fi
+        # command substitution removes any trailing newlines, so we have to add
+        # a non-newline ending, we randomly chose "b", then remove it.
+        content=$($readsudo cat "$file"; echo b) content=${content%b}
+        
         # we aren't using regex because we want to match strings,
         # but we also want our match to start at the beginning of a line,
         # or the beginning of the file, and to end at a line ending.
@@ -97,7 +90,7 @@ as a single LINE_SET. Appended text is output to the terminal.
         local end="
 *"
         for string in "${strings[@]}"; do
-            [[ $file_content != $start"$string"$end ]] && $writesudo tee -a "$file"<<<"$string"
+            [[ $content != $start"$string"$end ]] && $writesudo tee -a "$file"<<<"$string"
         done
     else
         for string in "${strings[@]}"; do

diff --git a/appendu-function b/appendu-function
index 7749aa47e7fafa3b29c5b158a149ba7e5995e690..6c97f6cb5f57914469c38d54a6445757a34506c0 100644 (file)
--- a/appendu-function
+++ b/appendu-function
@@ -15,7 +15,7 @@ as a single LINE_SET. Appended text is output to the terminal.
   --      stop processing arguments
   --help  display this message"
 
-    local readsudo writesudo x strings string
+    local readsudo writesudo x strings string content
     local dosudo=true
     
     while true; do
@@ -42,11 +42,10 @@ as a single LINE_SET. Appended text is output to the terminal.
     local file="$1"
     shift
 
-    local readsudo=false
     local file_exists=false
     if [[ -e $file ]]; then
         file_exists=true
-        [[ -r $file ]] || readsudo=true
+        [[ -r $file ]] || readsudo=sudo
         [[ -w $file ]] || writesudo=sudo
     else
         local dir="$(dirname "$file")"
@@ -78,16 +77,10 @@ as a single LINE_SET. Appended text is output to the terminal.
         # so sed only does what it always does when it was supposed to modify a file,
         # which is append a newline if there was none.
         sed -ie '$a\' "$file"
-        # this removes any trailing newline in the var, so we add it back on,
-        # because we want a consistent ending to match
-        local file_content
-        if $readsudo; then
-            file_content="$(sudo cat "$file")
-"
-        else
-            file_content="$(<"$file")
-"
-        fi
+        # command substitution removes any trailing newlines, so we have to add
+        # a non-newline ending, we randomly chose "b", then remove it.
+        content=$($readsudo cat "$file"; echo b) content=${content%b}
+        
         # we aren't using regex because we want to match strings,
         # but we also want our match to start at the beginning of a line,
         # or the beginning of the file, and to end at a line ending.
@@ -97,7 +90,7 @@ as a single LINE_SET. Appended text is output to the terminal.
         local end="
 *"
         for string in "${strings[@]}"; do
-            [[ $file_content != $start"$string"$end ]] && $writesudo tee -a "$file"<<<"$string"
+            [[ $content != $start"$string"$end ]] && $writesudo tee -a "$file"<<<"$string"
         done
     else
         for string in "${strings[@]}"; do