Bash prompt execute command every time a new prompt is displayed

up vote
6
down vote

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I have the following prompt in bash which shows the current git branch:

PS1+="$(git_prompt)" #git_prompt is a function in my .bashrc

which works when I source the .bashrc, but not when I change the branch, so the PS1 var gets only evaluated when I source the .bashrc, but it should be evaluated every time a new prompt is displayed. How can this be accomplished with bash 4.3 ?

edited Feb 3 '16 at 15:30

Jeff Schaller

32.6k849110

asked Feb 3 '16 at 15:26

danielr1996

185210

add a commentÂ |Â

up vote
6
down vote

favorite

I have the following prompt in bash which shows the current git branch:

PS1+="$(git_prompt)" #git_prompt is a function in my .bashrc

edited Feb 3 '16 at 15:30

Jeff Schaller

32.6k849110

asked Feb 3 '16 at 15:26

danielr1996

185210

add a commentÂ |Â

up vote
6
down vote

favorite

I have the following prompt in bash which shows the current git branch:

PS1+="$(git_prompt)" #git_prompt is a function in my .bashrc

edited Feb 3 '16 at 15:30

Jeff Schaller

32.6k849110

asked Feb 3 '16 at 15:26

danielr1996

185210

I have the following prompt in bash which shows the current git branch:

PS1+="$(git_prompt)" #git_prompt is a function in my .bashrc

bash prompt

edited Feb 3 '16 at 15:30

Jeff Schaller

32.6k849110

asked Feb 3 '16 at 15:26

danielr1996

185210

edited Feb 3 '16 at 15:30

Jeff Schaller

32.6k849110

asked Feb 3 '16 at 15:26

danielr1996

185210

edited Feb 3 '16 at 15:30

Jeff Schaller

32.6k849110

edited Feb 3 '16 at 15:30

Jeff Schaller

32.6k849110

edited Feb 3 '16 at 15:30

Jeff Schaller

32.6k849110

asked Feb 3 '16 at 15:26

danielr1996

185210

asked Feb 3 '16 at 15:26

danielr1996

185210

asked Feb 3 '16 at 15:26

danielr1996

185210

add a commentÂ |Â

4 Answers
4

active

oldest

votes

up vote
9
down vote

Your problem is that $(git_prompt) is evaluated to some constant string before it is added to $PS1. You have to add the code instead:

PS1+='$(git_prompt)'

answered Feb 3 '16 at 15:32

Hauke Laging

53.9k1282130

2

this gives the error bash: command substitution: line 1: syntax error near unexpected token )' bash: command substitution: line 1: git_prompt)'
â€“Â danielr1996
Feb 3 '16 at 15:36

1

That is really strange. Make a "backup" (oldPS1="$PS1") and then try: PS1='$(git_prompt) '
â€“Â Hauke Laging
Feb 3 '16 at 15:46

add a commentÂ |Â

up vote
4
down vote

I fixed it now by using this as prompt

PS1="$greenu $r@ $redh $r: $yellowW !$r $(git_prompt) n$yellow$ $r"

before I concatenated multiple strings to one PS1 string, there seemed to be the problem.
The trick is to write a before excuting the command with $(git_prompt).

So $(git_prompt) will be evaluated when the .bashrc is evaluated and

$(git_prompt) will be evaluated everytime a new prompt is displayed

answered Feb 3 '16 at 20:16

danielr1996

185210

4

For anyone who finds this in the future: Note the enclosing double-quotes " around the string. Using $(git_prompt) without those doesn't work.
â€“Â dthor
Sep 21 '16 at 0:28

@dthor thank you, it helped
â€“Â Herrgott
Feb 6 at 9:04

add a commentÂ |Â

up vote
1
down vote

try single quote in your ps1

PS1+='$(git_prompt)'

i also suggest my psOne function

psOne () 
 
 ps1tm=$1:-01;
 ps1tc=(30 31 32 33 34 35 36 37 38);
 PS1='$debian_chroot:+($debian_chroot)[33[$ps1tm;$ps1tc[$((RANDOM%$#ps1tc[@]))]m]u[33[$ps1tm;$ps1tc[$((RANDOM%$#ps1tc[@]))]m]@[33[$ps1tm;$ps1tc[$((RANDOM%$#ps1tc[@]))]m]h[33[$ps1tm;$ps1tc[$((RANDOM%$#ps1tc[@]))]m] :[33[$ps1tm;$ps1tc[$((RANDOM%$#ps1tc[@]))]m] w[33[$ps1tm;$ps1tc[$((RANDOM%$#ps1tc[@]))]m] $ '

enter image description here

edited Feb 3 '16 at 15:40

answered Feb 3 '16 at 15:34

Jonas

873515

This looks interesting, can you explain what the ps1tm is for?
â€“Â danielr1996
Feb 3 '16 at 16:37

@danielr1996 it the text mode (bold unbold blink underline 0..5, in this functions it's set to 01 if no argument exists
â€“Â Jonas
Feb 3 '16 at 16:44

add a commentÂ |Â

up vote
0
down vote

Want to see madness? This is how I construct my bash prompt:

# inspiration: http://www.stumbleupon.com/su/2LpQMi 
user_host_path="$debian_chroot:+($debian_chroot) "'u@h:w'
xterm_title='[e]0;'"$user_host_path"'a]'
[[ $TERM == xterm* || $TERM == rxvt* ]] && line1="$xterm_title"
git_branch='$(git_current_branch " (%s)")'
line1="$line1$user_host_path$git_branch "
line2='$ '
print_time='sed -e "s/./Ã‹Â™/g" -re "s/.6(..)$/ bash 1/"; date "+ %T"; >&2'
color_bold='[e[0;1m]'
color_reset='[e[0m]'
PROMPT_COMMAND="_rc_=$?;$print_time;((_rc_!=0)) && PS1='$line1n$color_bold[$_rc_]$color_reset $line2' || PS1='$line1n$line2'"
unset user_host_path xterm_title color_bold color_reset line1 line2 print_time git_branch

I'm not a big fan of colour.

answered Feb 3 '16 at 16:05

glenn jackman

47.7k265104

add a commentÂ |Â

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4 Answers
4

active

oldest

votes

4 Answers
4

active

oldest

votes

up vote
9
down vote

Your problem is that $(git_prompt) is evaluated to some constant string before it is added to $PS1. You have to add the code instead:

PS1+='$(git_prompt)'

answered Feb 3 '16 at 15:32

Hauke Laging

53.9k1282130

2

this gives the error bash: command substitution: line 1: syntax error near unexpected token )' bash: command substitution: line 1: git_prompt)'
â€“Â danielr1996
Feb 3 '16 at 15:36

1

That is really strange. Make a "backup" (oldPS1="$PS1") and then try: PS1='$(git_prompt) '
â€“Â Hauke Laging
Feb 3 '16 at 15:46

add a commentÂ |Â

up vote
9
down vote

Your problem is that $(git_prompt) is evaluated to some constant string before it is added to $PS1. You have to add the code instead:

PS1+='$(git_prompt)'

answered Feb 3 '16 at 15:32

Hauke Laging

53.9k1282130

2

this gives the error bash: command substitution: line 1: syntax error near unexpected token )' bash: command substitution: line 1: git_prompt)'
â€“Â danielr1996
Feb 3 '16 at 15:36

1

That is really strange. Make a "backup" (oldPS1="$PS1") and then try: PS1='$(git_prompt) '
â€“Â Hauke Laging
Feb 3 '16 at 15:46

add a commentÂ |Â

up vote
9
down vote

Your problem is that $(git_prompt) is evaluated to some constant string before it is added to $PS1. You have to add the code instead:

PS1+='$(git_prompt)'

answered Feb 3 '16 at 15:32

Hauke Laging

53.9k1282130

Your problem is that $(git_prompt) is evaluated to some constant string before it is added to $PS1. You have to add the code instead:

PS1+='$(git_prompt)'

answered Feb 3 '16 at 15:32

Hauke Laging

53.9k1282130

answered Feb 3 '16 at 15:32

Hauke Laging

53.9k1282130

answered Feb 3 '16 at 15:32

Hauke Laging

53.9k1282130

answered Feb 3 '16 at 15:32

Hauke Laging

53.9k1282130

2

this gives the error bash: command substitution: line 1: syntax error near unexpected token )' bash: command substitution: line 1: git_prompt)'
â€“Â danielr1996
Feb 3 '16 at 15:36

1

That is really strange. Make a "backup" (oldPS1="$PS1") and then try: PS1='$(git_prompt) '
â€“Â Hauke Laging
Feb 3 '16 at 15:46

add a commentÂ |Â

2

this gives the error bash: command substitution: line 1: syntax error near unexpected token )' bash: command substitution: line 1: git_prompt)'
â€“Â danielr1996
Feb 3 '16 at 15:36

1

That is really strange. Make a "backup" (oldPS1="$PS1") and then try: PS1='$(git_prompt) '
â€“Â Hauke Laging
Feb 3 '16 at 15:46

this gives the error bash: command substitution: line 1: syntax error near unexpected token )' bash: command substitution: line 1: git_prompt)'
â€“Â danielr1996
Feb 3 '16 at 15:36

That is really strange. Make a "backup" (oldPS1="$PS1") and then try: PS1='$(git_prompt) '
â€“Â Hauke Laging
Feb 3 '16 at 15:46

add a commentÂ |Â

up vote
4
down vote

I fixed it now by using this as prompt

PS1="$greenu $r@ $redh $r: $yellowW !$r $(git_prompt) n$yellow$ $r"

before I concatenated multiple strings to one PS1 string, there seemed to be the problem.
The trick is to write a before excuting the command with $(git_prompt).

So $(git_prompt) will be evaluated when the .bashrc is evaluated and

$(git_prompt) will be evaluated everytime a new prompt is displayed

answered Feb 3 '16 at 20:16

danielr1996

185210

4

For anyone who finds this in the future: Note the enclosing double-quotes " around the string. Using $(git_prompt) without those doesn't work.
â€“Â dthor
Sep 21 '16 at 0:28

@dthor thank you, it helped
â€“Â Herrgott
Feb 6 at 9:04

add a commentÂ |Â

up vote
4
down vote

I fixed it now by using this as prompt

PS1="$greenu $r@ $redh $r: $yellowW !$r $(git_prompt) n$yellow$ $r"

before I concatenated multiple strings to one PS1 string, there seemed to be the problem.
The trick is to write a before excuting the command with $(git_prompt).

So $(git_prompt) will be evaluated when the .bashrc is evaluated and

$(git_prompt) will be evaluated everytime a new prompt is displayed

answered Feb 3 '16 at 20:16

danielr1996

185210

4

For anyone who finds this in the future: Note the enclosing double-quotes " around the string. Using $(git_prompt) without those doesn't work.
â€“Â dthor
Sep 21 '16 at 0:28

@dthor thank you, it helped
â€“Â Herrgott
Feb 6 at 9:04

add a commentÂ |Â

up vote
4
down vote

I fixed it now by using this as prompt

PS1="$greenu $r@ $redh $r: $yellowW !$r $(git_prompt) n$yellow$ $r"

before I concatenated multiple strings to one PS1 string, there seemed to be the problem.
The trick is to write a before excuting the command with $(git_prompt).

So $(git_prompt) will be evaluated when the .bashrc is evaluated and

$(git_prompt) will be evaluated everytime a new prompt is displayed

answered Feb 3 '16 at 20:16

danielr1996

185210

I fixed it now by using this as prompt

PS1="$greenu $r@ $redh $r: $yellowW !$r $(git_prompt) n$yellow$ $r"

before I concatenated multiple strings to one PS1 string, there seemed to be the problem.
The trick is to write a before excuting the command with $(git_prompt).

So $(git_prompt) will be evaluated when the .bashrc is evaluated and

$(git_prompt) will be evaluated everytime a new prompt is displayed

answered Feb 3 '16 at 20:16

danielr1996

185210

answered Feb 3 '16 at 20:16

danielr1996

185210

answered Feb 3 '16 at 20:16

danielr1996

185210

answered Feb 3 '16 at 20:16

danielr1996

185210

4

For anyone who finds this in the future: Note the enclosing double-quotes " around the string. Using $(git_prompt) without those doesn't work.
â€“Â dthor
Sep 21 '16 at 0:28

@dthor thank you, it helped
â€“Â Herrgott
Feb 6 at 9:04

add a commentÂ |Â

4

For anyone who finds this in the future: Note the enclosing double-quotes " around the string. Using $(git_prompt) without those doesn't work.
â€“Â dthor
Sep 21 '16 at 0:28

@dthor thank you, it helped
â€“Â Herrgott
Feb 6 at 9:04

For anyone who finds this in the future: Note the enclosing double-quotes " around the string. Using $(git_prompt) without those doesn't work.
â€“Â dthor
Sep 21 '16 at 0:28

@dthor thank you, it helped
â€“Â Herrgott
Feb 6 at 9:04

add a commentÂ |Â

up vote
1
down vote

try single quote in your ps1

PS1+='$(git_prompt)'

i also suggest my psOne function

psOne () 
 
 ps1tm=$1:-01;
 ps1tc=(30 31 32 33 34 35 36 37 38);
 PS1='$debian_chroot:+($debian_chroot)[33[$ps1tm;$ps1tc[$((RANDOM%$#ps1tc[@]))]m]u[33[$ps1tm;$ps1tc[$((RANDOM%$#ps1tc[@]))]m]@[33[$ps1tm;$ps1tc[$((RANDOM%$#ps1tc[@]))]m]h[33[$ps1tm;$ps1tc[$((RANDOM%$#ps1tc[@]))]m] :[33[$ps1tm;$ps1tc[$((RANDOM%$#ps1tc[@]))]m] w[33[$ps1tm;$ps1tc[$((RANDOM%$#ps1tc[@]))]m] $ '

enter image description here

edited Feb 3 '16 at 15:40

answered Feb 3 '16 at 15:34

Jonas

873515

This looks interesting, can you explain what the ps1tm is for?
â€“Â danielr1996
Feb 3 '16 at 16:37

@danielr1996 it the text mode (bold unbold blink underline 0..5, in this functions it's set to 01 if no argument exists
â€“Â Jonas
Feb 3 '16 at 16:44

add a commentÂ |Â

up vote
1
down vote

try single quote in your ps1

PS1+='$(git_prompt)'

i also suggest my psOne function

psOne () 
 
 ps1tm=$1:-01;
 ps1tc=(30 31 32 33 34 35 36 37 38);
 PS1='$debian_chroot:+($debian_chroot)[33[$ps1tm;$ps1tc[$((RANDOM%$#ps1tc[@]))]m]u[33[$ps1tm;$ps1tc[$((RANDOM%$#ps1tc[@]))]m]@[33[$ps1tm;$ps1tc[$((RANDOM%$#ps1tc[@]))]m]h[33[$ps1tm;$ps1tc[$((RANDOM%$#ps1tc[@]))]m] :[33[$ps1tm;$ps1tc[$((RANDOM%$#ps1tc[@]))]m] w[33[$ps1tm;$ps1tc[$((RANDOM%$#ps1tc[@]))]m] $ '

enter image description here

edited Feb 3 '16 at 15:40

answered Feb 3 '16 at 15:34

Jonas

873515

This looks interesting, can you explain what the ps1tm is for?
â€“Â danielr1996
Feb 3 '16 at 16:37

@danielr1996 it the text mode (bold unbold blink underline 0..5, in this functions it's set to 01 if no argument exists
â€“Â Jonas
Feb 3 '16 at 16:44

add a commentÂ |Â

up vote
1
down vote

try single quote in your ps1

PS1+='$(git_prompt)'

i also suggest my psOne function

psOne () 
 
 ps1tm=$1:-01;
 ps1tc=(30 31 32 33 34 35 36 37 38);
 PS1='$debian_chroot:+($debian_chroot)[33[$ps1tm;$ps1tc[$((RANDOM%$#ps1tc[@]))]m]u[33[$ps1tm;$ps1tc[$((RANDOM%$#ps1tc[@]))]m]@[33[$ps1tm;$ps1tc[$((RANDOM%$#ps1tc[@]))]m]h[33[$ps1tm;$ps1tc[$((RANDOM%$#ps1tc[@]))]m] :[33[$ps1tm;$ps1tc[$((RANDOM%$#ps1tc[@]))]m] w[33[$ps1tm;$ps1tc[$((RANDOM%$#ps1tc[@]))]m] $ '

enter image description here

edited Feb 3 '16 at 15:40

answered Feb 3 '16 at 15:34

Jonas

873515

try single quote in your ps1

PS1+='$(git_prompt)'

i also suggest my psOne function

psOne () 
 
 ps1tm=$1:-01;
 ps1tc=(30 31 32 33 34 35 36 37 38);
 PS1='$debian_chroot:+($debian_chroot)[33[$ps1tm;$ps1tc[$((RANDOM%$#ps1tc[@]))]m]u[33[$ps1tm;$ps1tc[$((RANDOM%$#ps1tc[@]))]m]@[33[$ps1tm;$ps1tc[$((RANDOM%$#ps1tc[@]))]m]h[33[$ps1tm;$ps1tc[$((RANDOM%$#ps1tc[@]))]m] :[33[$ps1tm;$ps1tc[$((RANDOM%$#ps1tc[@]))]m] w[33[$ps1tm;$ps1tc[$((RANDOM%$#ps1tc[@]))]m] $ '

enter image description here

edited Feb 3 '16 at 15:40

answered Feb 3 '16 at 15:34

Jonas

873515

edited Feb 3 '16 at 15:40

answered Feb 3 '16 at 15:34

Jonas

873515

answered Feb 3 '16 at 15:34

Jonas

873515

answered Feb 3 '16 at 15:34

Jonas

873515

This looks interesting, can you explain what the ps1tm is for?
â€“Â danielr1996
Feb 3 '16 at 16:37

@danielr1996 it the text mode (bold unbold blink underline 0..5, in this functions it's set to 01 if no argument exists
â€“Â Jonas
Feb 3 '16 at 16:44

add a commentÂ |Â

This looks interesting, can you explain what the ps1tm is for?
â€“Â danielr1996
Feb 3 '16 at 16:37

@danielr1996 it the text mode (bold unbold blink underline 0..5, in this functions it's set to 01 if no argument exists
â€“Â Jonas
Feb 3 '16 at 16:44

This looks interesting, can you explain what the ps1tm is for?
â€“Â danielr1996
Feb 3 '16 at 16:37

@danielr1996 it the text mode (bold unbold blink underline 0..5, in this functions it's set to 01 if no argument exists
â€“Â Jonas
Feb 3 '16 at 16:44

add a commentÂ |Â

up vote
0
down vote

Want to see madness? This is how I construct my bash prompt:

# inspiration: http://www.stumbleupon.com/su/2LpQMi 
user_host_path="$debian_chroot:+($debian_chroot) "'u@h:w'
xterm_title='[e]0;'"$user_host_path"'a]'
[[ $TERM == xterm* || $TERM == rxvt* ]] && line1="$xterm_title"
git_branch='$(git_current_branch " (%s)")'
line1="$line1$user_host_path$git_branch "
line2='$ '
print_time='sed -e "s/./Ã‹Â™/g" -re "s/.6(..)$/ bash 1/"; date "+ %T"; >&2'
color_bold='[e[0;1m]'
color_reset='[e[0m]'
PROMPT_COMMAND="_rc_=$?;$print_time;((_rc_!=0)) && PS1='$line1n$color_bold[$_rc_]$color_reset $line2' || PS1='$line1n$line2'"
unset user_host_path xterm_title color_bold color_reset line1 line2 print_time git_branch

I'm not a big fan of colour.

answered Feb 3 '16 at 16:05

glenn jackman

47.7k265104

add a commentÂ |Â

up vote
0
down vote

Want to see madness? This is how I construct my bash prompt:

# inspiration: http://www.stumbleupon.com/su/2LpQMi 
user_host_path="$debian_chroot:+($debian_chroot) "'u@h:w'
xterm_title='[e]0;'"$user_host_path"'a]'
[[ $TERM == xterm* || $TERM == rxvt* ]] && line1="$xterm_title"
git_branch='$(git_current_branch " (%s)")'
line1="$line1$user_host_path$git_branch "
line2='$ '
print_time='sed -e "s/./Ã‹Â™/g" -re "s/.6(..)$/ bash 1/"; date "+ %T"; >&2'
color_bold='[e[0;1m]'
color_reset='[e[0m]'
PROMPT_COMMAND="_rc_=$?;$print_time;((_rc_!=0)) && PS1='$line1n$color_bold[$_rc_]$color_reset $line2' || PS1='$line1n$line2'"
unset user_host_path xterm_title color_bold color_reset line1 line2 print_time git_branch

I'm not a big fan of colour.

answered Feb 3 '16 at 16:05

glenn jackman

47.7k265104

add a commentÂ |Â

up vote
0
down vote

Want to see madness? This is how I construct my bash prompt:

# inspiration: http://www.stumbleupon.com/su/2LpQMi 
user_host_path="$debian_chroot:+($debian_chroot) "'u@h:w'
xterm_title='[e]0;'"$user_host_path"'a]'
[[ $TERM == xterm* || $TERM == rxvt* ]] && line1="$xterm_title"
git_branch='$(git_current_branch " (%s)")'
line1="$line1$user_host_path$git_branch "
line2='$ '
print_time='sed -e "s/./Ã‹Â™/g" -re "s/.6(..)$/ bash 1/"; date "+ %T"; >&2'
color_bold='[e[0;1m]'
color_reset='[e[0m]'
PROMPT_COMMAND="_rc_=$?;$print_time;((_rc_!=0)) && PS1='$line1n$color_bold[$_rc_]$color_reset $line2' || PS1='$line1n$line2'"
unset user_host_path xterm_title color_bold color_reset line1 line2 print_time git_branch

I'm not a big fan of colour.

answered Feb 3 '16 at 16:05

glenn jackman

47.7k265104

Want to see madness? This is how I construct my bash prompt:

# inspiration: http://www.stumbleupon.com/su/2LpQMi 
user_host_path="$debian_chroot:+($debian_chroot) "'u@h:w'
xterm_title='[e]0;'"$user_host_path"'a]'
[[ $TERM == xterm* || $TERM == rxvt* ]] && line1="$xterm_title"
git_branch='$(git_current_branch " (%s)")'
line1="$line1$user_host_path$git_branch "
line2='$ '
print_time='sed -e "s/./Ã‹Â™/g" -re "s/.6(..)$/ bash 1/"; date "+ %T"; >&2'
color_bold='[e[0;1m]'
color_reset='[e[0m]'
PROMPT_COMMAND="_rc_=$?;$print_time;((_rc_!=0)) && PS1='$line1n$color_bold[$_rc_]$color_reset $line2' || PS1='$line1n$line2'"
unset user_host_path xterm_title color_bold color_reset line1 line2 print_time git_branch

I'm not a big fan of colour.

answered Feb 3 '16 at 16:05

glenn jackman

47.7k265104

answered Feb 3 '16 at 16:05

glenn jackman

47.7k265104

answered Feb 3 '16 at 16:05

glenn jackman

47.7k265104

answered Feb 3 '16 at 16:05

glenn jackman

47.7k265104

add a commentÂ |Â

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