summaryrefslogtreecommitdiff
path: root/.bash_prompt
blob: 3b9b62c455311b58bb9b9a0ed25f200ef84ed621 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
# Environment variables:
#
# PS1_SHOWHOSTNAME
#       'auto' (default):       Only show hostname over SSH
#       'yes':                  Always show hostname
#       anything else:          Never show hostname


if [ "${TERM}" = dumb ]
then
    return
fi


__show-hostname ()
{
    case ${PS1_SHOWHOSTNAME} in
        (''|auto)
            [ "${SSH_CONNECTION}" ];;
        (yes)
            true;;
        (*)
            false;;
    esac
}

__have-gitprompt ()
{
    [ -f /usr/lib/git-core/git-sh-prompt ]
}

__set-title ()
{
    local title
    local git_root=$(git root 2> /dev/null)

    if [ ${git_root} ]
    then
        title=$(basename ${git_root})
    else
        local path=${PWD/~/\~}

        if __show-hostname
        then
            title="${USER}@${HOSTNAME}:${path}"
        else
            title="${USER}:${path}"
        fi
    fi

    # Cf. console_codes(4):
    #
    #   ESC ] 2 ; txt ST        Set window title to txt.
    #
    # ST is a "string terminator", either "ESC \" or "BEL".

    echo -ne "\E]2;${title}\a"
}

# In order to know how much space PS1 takes, Bash needs us to delimit
# non-printing characters with \[ and \].
__start-nonprinting ()
{
    if [ ${BUILDING_PS1} ]
    then
        echo -en '\['
    fi
}

__end-nonprinting ()
{
    if [ ${BUILDING_PS1} ]
    then
        echo -en '\]'
    fi
}

__fontify ()
{
    local -A codes=(
        [bold]=1
        [dim]=2
        [red]=31
        [green]=32
        [blue]=34
    )

    local text=$1
    shift

    __start-nonprinting
    echo -en '\E['

    for ((i=1; i<=$#; i++))
    do
        echo -en ${codes[${!i}]}

        if ((i<$#))
        then
            echo -en ';'
        else
            echo -en 'm'
        fi
    done

    __end-nonprinting

    echo -en "${text}"
    __start-nonprinting
    echo -en '\E[0m'
    __end-nonprinting
}

__set-prompt ()
{
    local last_status=$1
    BUILDING_PS1=t
    PS1=''

    if [ ${last_status} -ne 0 ]
    then
        PS1+=$(__fontify "${last_status} " bold red) 
    fi

    PS1+=$(__fontify '\$' dim)
    PS1+=' '

    unset BUILDING_PS1
}

__current-column ()
{
    # Cf. console_codes(4) ยง ECMA-48 Status Report Commands

    local position
    read -sdR -p$'\E[6n' position

    local pattern='\[[0-9]+;([0-9]+)'

    if [[ ${position} =~ ${pattern} ]]
    then
        echo ${BASH_REMATCH[1]}
    else
        echo 0
    fi
}

__fill-line ()
{
    local char=$1
    shift

    local line=''

    for ((i=$(__current-column); i<COLUMNS; i++))
    do
        line+=${char}
    done

    # If we do not add a newline, whatever comes after will be shoved
    # offscreen when autowrap is off.
    line+='\n'

    __fontify ${line} $@
}

__draw-rule ()
{
    __fill-line โ€” dim
}

__finish-line ()
{
    __fill-line / dim red
}

__write-context ()
{
    local context=''

    context+=$(__fontify "${USER}" green)

    if __show-hostname
    then
        context+=$(__fontify '@' dim)
        context+=$(__fontify "${HOSTNAME}" bold green)
    fi

    context+=$(__fontify : dim)
    context+=$(__fontify "${PWD/~/\~}" bold blue)

    if [ ${PS1_SHOWGITSTATUS} ]
    then
        context+=$(__fontify "$(__git_ps1 '(%s)')" red)
    fi

    echo -n "${context} "
}

__refresh-terminal ()
{
    local last_status=$?
    local last_column=$(__current-column)

    __set-title

    if [ ${last_column} -ne 1 ]
    then
        __finish-line
    fi

    __write-context
    __draw-rule
    __set-prompt ${last_status}
}


if __have-gitprompt
then
    . /usr/lib/git-core/git-sh-prompt
    GIT_PS1_SHOWDIRTYSTATE=t
    GIT_PS1_SHOWUPSTREAM=auto

    PS1_SHOWGITSTATUS=t
fi

export PROMPT_COMMAND=__refresh-terminal