Season bash to taste

[ COND ]                → test COND
if COND then LIST fi    → COND && LIST
echo -en TEXT           → printf $'TEXT'
for …                   → IFS=c eval 'VAR="${ARRAY[*]}"
[ A -op B ]             → ((A OP B))

1 files changed, 63 insertions, 79 deletions

diff --git a/.bash_prompt b/.bash_prompt
index e3c9a87..b00fb8f 100644
--- a/.bash_prompt
+++ b/.bash_prompt
@@ -12,7 +12,7 @@ __show-hostname ()
 {
     case ${PS1_SHOWHOSTNAME} in
         (''|auto)
-            [ "${SSH_CONNECTION}" ];;
+            test "${SSH_CONNECTION}";;
         (yes)
             true;;
         (*)
@@ -22,16 +22,13 @@ __show-hostname ()
 
 __have-gitprompt ()
 {
-    [ -f /usr/lib/git-core/git-sh-prompt ]
+    test -f /usr/lib/git-core/git-sh-prompt
 }
 
 __set-title ()
 {
     local title=${USER}
-    if __show-hostname
-    then
-        title+="@${HOSTNAME}"
-    fi
+    __show-hostname && title+=@${HOSTNAME}
     title+=:
     title+=${PWD/~/\~}
 
@@ -41,30 +38,26 @@ __set-title ()
     #
     # ST is a "string terminator", either "ESC \" or "BEL".
 
-    echo -ne "\E]2;${title}\a"
+    printf $'\E]2;%s\a' "${title}"
 }
 
-# In order to know how much space a prompt takes, Bash needs us to
-# delimit non-printing characters with \[ and \].
+# Bash relies on \[ \] to distinguish non-printing characters in prompts.
 __start-nonprinting ()
 {
-    if [ ${BUILDING_PS} ]
-    then
-        echo -en '\['
-    fi
+    test ${BUILDING_PS} && printf '\['
 }
 
 __end-nonprinting ()
 {
-    if [ ${BUILDING_PS} ]
-    then
-        echo -en '\]'
-    fi
+    test ${BUILDING_PS} && printf '\]'
 }
 
 __fontify ()
 {
-    local -A codes=(
+    local -r text=$1
+    shift
+
+    local -Ar codes=(
         [bold]=1
         [dim]=2
         [reverse]=7
@@ -73,91 +66,88 @@ __fontify ()
         [blue]=34
     )
 
-    local text=$1
-    shift
-
-    __start-nonprinting
-
-    echo -en '\E['
-
-    local i
-    for ((i=1; i<=$#; i++))
+    local -a params=()
+    local c
+    for c
     do
-        echo -en ${codes[${!i}]}
-
-        if ((i<$#))
-        then
-            echo -en ';'
-        else
-            echo -en 'm'
-        fi
+        params+=(${codes[${c}]})
     done
 
+    local params_seq
+    IFS=';' eval 'params_seq="${params[*]}"'
+
+    __start-nonprinting
+    printf $'\E[%sm' "${params_seq}"
     __end-nonprinting
 
-    echo -en "${text}"
+    printf %s "${text}"
 
     __start-nonprinting
-    echo -en '\E[0m'
+    printf $'\E[0m'
     __end-nonprinting
 }
 
 __current-column ()
 {
-    # Cf. console_codes(4) § ECMA-48 Status Report Commands
+    # Cf. console_codes(4) § ECMA-48 Status Report Commands.
 
     local position
     read -sdR -p$'\E[6n' position
 
-    local pattern='\[[0-9]+;([0-9]+)'
+    local -r pattern='\[[0-9]+;([0-9]+)'
 
-    if [[ ${position} =~ ${pattern} ]]
-    then
-        echo ${BASH_REMATCH[1]}
-    else
+    [[ ${position} =~ ${pattern} ]] || {
         echo 0
-    fi
+        return
+    }
+    echo ${BASH_REMATCH[1]}
 }
 
 __signal-no-newline ()
 {
-    echo $(__fontify ∅ bold red)
+    __fontify ∅ bold red
+    echo
 }
 
 __draw-rule ()
 {
-    local i line
-
-    for ((i=$(__current-column); i<COLUMNS; i++))
-    do
-        line+=─
-    done
-
-    # If we do not add a newline, whatever comes after will be shoved
-    # offscreen when autowrap is off.
-    line+='\n'
-
-    __fontify ${line} $@
+    local -ir pos=$(__current-column)
+    local -ir rule_len=$((COLUMNS-pos))
+
+    local rule
+    # Hey Future Me 👋 Breaking this down:
+    # -v rule       "put this in LINE, do not write to stdout"
+    # "%…s"         "pad string…"
+    #  -            " … with spaces…"
+    #  *            " … with length given by next argument"
+    # ${rule_len}   (padding length)
+    # ∅             (psych! no arg for %s, default to null string)
+    printf -v rule '%-*s' ${rule_len}
+    rule=${rule// /─}
+
+    # Flush line to avoid future text being shoved offscreen when autowrap
+    # is off.
+    rule+=$'\n'
+
+    __fontify "${rule}" "$@"
 }
 
 __write-context ()
 {
     __fontify '\u' green
 
-    if __show-hostname
-    then
+    __show-hostname && {
         __fontify @ dim
         __fontify '\H' bold green
-    fi
+    }
 
     printf ' '
     __fontify '\w' bold blue
 
-    if [ ${PS1_SHOWGITSTATUS} ]
-    then
+    test "${PS1_SHOWGITSTATUS}" && {
         printf ' '
         __fontify "$(__git_ps1 '(%s)')" red
-    fi
+    }
 }
 
 __smart-term/set-ps1 ()
@@ -171,18 +161,16 @@ __smart-term/set-ps1 ()
 
 __smart-term/refresh ()
 {
-    local last_status=$?
+    local -ir rc=$?
 
     __set-title
 
-    if [ $(__current-column) -ne 1 ]
-    then
-        __signal-no-newline
-    fi
+    local -ir pos=$(__current-column)
+    ((pos != 1)) && __signal-no-newline
 
-    if [ ${last_status} -ne 0 ]
+    if ((rc))
     then
-        __fontify "${last_status} " bold red
+        __fontify "${rc} " bold red
         __draw-rule dim red
     else
         __draw-rule dim
@@ -193,16 +181,15 @@ __smart-term/refresh ()
 
 __smart-term/init ()
 {
-    ### Prompts.
+    # Prompts.
 
-    if __have-gitprompt
-    then
+    __have-gitprompt && {
         . /usr/lib/git-core/git-sh-prompt
         GIT_PS1_SHOWDIRTYSTATE=t
         GIT_PS1_SHOWUPSTREAM=auto
 
         PS1_SHOWGITSTATUS=t
-    fi
+    }
 
     PROMPT_COMMAND=__smart-term/refresh
 
@@ -211,15 +198,12 @@ __smart-term/init ()
         __fontify '… ' dim
     )
 
-    ### Bindings.
+    # Bindings.
 
     bind -f ~/.bash_inputrc
 
     # Unset the TTY's "stop" char, so that readline receives C-s.
-    if tty -s
-    then
-        stty stop ''
-    fi
+    tty -s && stty stop ''
 }
 
 __dumb-term/set-ps1 ()