Mixing
How to modify a variable in a file
1
I have a config file like this:
# Default LIST="nil"
LIST="element1 element2 element3"
What would be the simplest way to modify LIST from a shell script?
text-processing scripting
asked Jan 23 at 10:03
Alberto Salvia NovellaAlberto Salvia Novella
1105
add a comment |
1
I have a config file like this:
# Default LIST="nil"
LIST="element1 element2 element3"
What would be the simplest way to modify LIST from a shell script?
text-processing scripting
asked Jan 23 at 10:03
Alberto Salvia NovellaAlberto Salvia Novella
1105
1
Can you elaborate on what you have in mind? What's the goal and what have you tried so far?
– eblock
Jan 23 at 10:06
I believe the rest of the details would convolute the question.
– Alberto Salvia Novella
Jan 23 at 10:13
1
@AlbertoSalviaNovella I believe you should state what you are after. If you have multiple strings in a variable you probably want an array variable likelist=( element1 element2 element3 )
– Valentin Bajrami
Jan 23 at 10:19
The variable I want to modify is already defined as a single string, but thanks for the point.
– Alberto Salvia Novella
Jan 23 at 10:43
add a comment |
1
1
1
I have a config file like this:
# Default LIST="nil"
LIST="element1 element2 element3"
What would be the simplest way to modify LIST from a shell script?
text-processing scripting
asked Jan 23 at 10:03
Alberto Salvia NovellaAlberto Salvia Novella
1105
I have a config file like this:
# Default LIST="nil"
LIST="element1 element2 element3"
What would be the simplest way to modify LIST from a shell script?
text-processing scripting
text-processing scripting
asked Jan 23 at 10:03
Alberto Salvia NovellaAlberto Salvia Novella
1105
asked Jan 23 at 10:03
Alberto Salvia NovellaAlberto Salvia Novella
1105
edited Jan 23 at 11:31
Alberto Salvia Novella
asked Jan 23 at 10:03
Alberto Salvia NovellaAlberto Salvia Novella
1105
asked Jan 23 at 10:03
Alberto Salvia NovellaAlberto Salvia Novella
1105
asked Jan 23 at 10:03
Alberto Salvia NovellaAlberto Salvia Novella
1105
1105
1
Can you elaborate on what you have in mind? What's the goal and what have you tried so far?
– eblock
Jan 23 at 10:06
I believe the rest of the details would convolute the question.
– Alberto Salvia Novella
Jan 23 at 10:13
1
@AlbertoSalviaNovella I believe you should state what you are after. If you have multiple strings in a variable you probably want an array variable likelist=( element1 element2 element3 )
– Valentin Bajrami
Jan 23 at 10:19
The variable I want to modify is already defined as a single string, but thanks for the point.
– Alberto Salvia Novella
Jan 23 at 10:43
add a comment |
1
Can you elaborate on what you have in mind? What's the goal and what have you tried so far?
– eblock
Jan 23 at 10:06
I believe the rest of the details would convolute the question.
– Alberto Salvia Novella
Jan 23 at 10:13
1
@AlbertoSalviaNovella I believe you should state what you are after. If you have multiple strings in a variable you probably want an array variable likelist=( element1 element2 element3 )
– Valentin Bajrami
Jan 23 at 10:19
The variable I want to modify is already defined as a single string, but thanks for the point.
– Alberto Salvia Novella
Jan 23 at 10:43
1
1
Can you elaborate on what you have in mind? What's the goal and what have you tried so far?
– eblock
Jan 23 at 10:06
Can you elaborate on what you have in mind? What's the goal and what have you tried so far?
– eblock
Jan 23 at 10:06
I believe the rest of the details would convolute the question.
– Alberto Salvia Novella
Jan 23 at 10:13
I believe the rest of the details would convolute the question.
– Alberto Salvia Novella
Jan 23 at 10:13
1
1
@AlbertoSalviaNovella I believe you should state what you are after. If you have multiple strings in a variable you probably want an array variable like
list=( element1 element2 element3 )– Valentin Bajrami
Jan 23 at 10:19
@AlbertoSalviaNovella I believe you should state what you are after. If you have multiple strings in a variable you probably want an array variable like
list=( element1 element2 element3 )– Valentin Bajrami
Jan 23 at 10:19
The variable I want to modify is already defined as a single string, but thanks for the point.
– Alberto Salvia Novella
Jan 23 at 10:43
The variable I want to modify is already defined as a single string, but thanks for the point.
– Alberto Salvia Novella
Jan 23 at 10:43
add a comment |
2 Answers
2
active
oldest
votes
3
Use sed:
sed -i 's/LIST=.*/LIST="element4 element5"/' config_file
If you only want LIST to be updated if it's not commented, add ^ (start of line):
sed -i 's/^LIST=.*/LIST="element4 element5"/' config_file
answered Jan 23 at 10:07
RoVoRoVo
3,247216
That solves my problem. Thank you ;)
– Alberto Salvia Novella
Jan 23 at 10:44
I detected an issue. If LIST is in COMMENT, it will also be changed there.
– Alberto Salvia Novella
Jan 23 at 11:31
Thats not a bug, it's a feature ;-) See my update.
– RoVo
Jan 23 at 11:34
Now it works nicely :P
– Alberto Salvia Novella
Jan 23 at 12:21
add a comment |
1
Same answer as the accepted one, but ready to use in a script. In case someone finds it useful:
#! /bin/bash
# (GPL3+) Alberto Salvia Novella (es20490446e)
modifyVariableInFile () {
variable="${1}"
content="${2}"
file="${3}"
if [ ! -f "${file}" ]; then
echo "modifyVariableInFile: file doesn't exist: ${file}"
exit 1
fi
sed -i "s/^${variable}=.*/${variable}="${content}"/" "${file}"
}
modifyVariableInFile ${@}
answered Jan 23 at 10:46
Alberto Salvia NovellaAlberto Salvia Novella
1105
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
3
Use sed:
sed -i 's/LIST=.*/LIST="element4 element5"/' config_file
If you only want LIST to be updated if it's not commented, add ^ (start of line):
sed -i 's/^LIST=.*/LIST="element4 element5"/' config_file
answered Jan 23 at 10:07
RoVoRoVo
3,247216
That solves my problem. Thank you ;)
– Alberto Salvia Novella
Jan 23 at 10:44
I detected an issue. If LIST is in COMMENT, it will also be changed there.
– Alberto Salvia Novella
Jan 23 at 11:31
Thats not a bug, it's a feature ;-) See my update.
– RoVo
Jan 23 at 11:34
Now it works nicely :P
– Alberto Salvia Novella
Jan 23 at 12:21
add a comment |
3
Use sed:
sed -i 's/LIST=.*/LIST="element4 element5"/' config_file
If you only want LIST to be updated if it's not commented, add ^ (start of line):
sed -i 's/^LIST=.*/LIST="element4 element5"/' config_file
answered Jan 23 at 10:07
RoVoRoVo
3,247216
That solves my problem. Thank you ;)
– Alberto Salvia Novella
Jan 23 at 10:44
I detected an issue. If LIST is in COMMENT, it will also be changed there.
– Alberto Salvia Novella
Jan 23 at 11:31
Thats not a bug, it's a feature ;-) See my update.
– RoVo
Jan 23 at 11:34
Now it works nicely :P
– Alberto Salvia Novella
Jan 23 at 12:21
add a comment |
3
3
3
Use sed:
sed -i 's/LIST=.*/LIST="element4 element5"/' config_file
If you only want LIST to be updated if it's not commented, add ^ (start of line):
sed -i 's/^LIST=.*/LIST="element4 element5"/' config_file
answered Jan 23 at 10:07
RoVoRoVo
3,247216
Use sed:
sed -i 's/LIST=.*/LIST="element4 element5"/' config_file
If you only want LIST to be updated if it's not commented, add ^ (start of line):
sed -i 's/^LIST=.*/LIST="element4 element5"/' config_file
answered Jan 23 at 10:07
RoVoRoVo
3,247216
edited Jan 23 at 11:33
answered Jan 23 at 10:07
RoVoRoVo
3,247216
answered Jan 23 at 10:07
RoVoRoVo
3,247216
answered Jan 23 at 10:07
RoVoRoVo
3,247216
3,247216
That solves my problem. Thank you ;)
– Alberto Salvia Novella
Jan 23 at 10:44
I detected an issue. If LIST is in COMMENT, it will also be changed there.
– Alberto Salvia Novella
Jan 23 at 11:31
Thats not a bug, it's a feature ;-) See my update.
– RoVo
Jan 23 at 11:34
Now it works nicely :P
– Alberto Salvia Novella
Jan 23 at 12:21
add a comment |
That solves my problem. Thank you ;)
– Alberto Salvia Novella
Jan 23 at 10:44
I detected an issue. If LIST is in COMMENT, it will also be changed there.
– Alberto Salvia Novella
Jan 23 at 11:31
Thats not a bug, it's a feature ;-) See my update.
– RoVo
Jan 23 at 11:34
Now it works nicely :P
– Alberto Salvia Novella
Jan 23 at 12:21
That solves my problem. Thank you ;)
– Alberto Salvia Novella
Jan 23 at 10:44
That solves my problem. Thank you ;)
– Alberto Salvia Novella
Jan 23 at 10:44
I detected an issue. If LIST is in COMMENT, it will also be changed there.
– Alberto Salvia Novella
Jan 23 at 11:31
I detected an issue. If LIST is in COMMENT, it will also be changed there.
– Alberto Salvia Novella
Jan 23 at 11:31
Thats not a bug, it's a feature ;-) See my update.
– RoVo
Jan 23 at 11:34
Thats not a bug, it's a feature ;-) See my update.
– RoVo
Jan 23 at 11:34
Now it works nicely :P
– Alberto Salvia Novella
Jan 23 at 12:21
Now it works nicely :P
– Alberto Salvia Novella
Jan 23 at 12:21
add a comment |
1
Same answer as the accepted one, but ready to use in a script. In case someone finds it useful:
#! /bin/bash
# (GPL3+) Alberto Salvia Novella (es20490446e)
modifyVariableInFile () {
variable="${1}"
content="${2}"
file="${3}"
if [ ! -f "${file}" ]; then
echo "modifyVariableInFile: file doesn't exist: ${file}"
exit 1
fi
sed -i "s/^${variable}=.*/${variable}="${content}"/" "${file}"
}
modifyVariableInFile ${@}
answered Jan 23 at 10:46
Alberto Salvia NovellaAlberto Salvia Novella
1105
add a comment |
1
Same answer as the accepted one, but ready to use in a script. In case someone finds it useful:
#! /bin/bash
# (GPL3+) Alberto Salvia Novella (es20490446e)
modifyVariableInFile () {
variable="${1}"
content="${2}"
file="${3}"
if [ ! -f "${file}" ]; then
echo "modifyVariableInFile: file doesn't exist: ${file}"
exit 1
fi
sed -i "s/^${variable}=.*/${variable}="${content}"/" "${file}"
}
modifyVariableInFile ${@}
answered Jan 23 at 10:46
Alberto Salvia NovellaAlberto Salvia Novella
1105
add a comment |
1
1
1
Same answer as the accepted one, but ready to use in a script. In case someone finds it useful:
#! /bin/bash
# (GPL3+) Alberto Salvia Novella (es20490446e)
modifyVariableInFile () {
variable="${1}"
content="${2}"
file="${3}"
if [ ! -f "${file}" ]; then
echo "modifyVariableInFile: file doesn't exist: ${file}"
exit 1
fi
sed -i "s/^${variable}=.*/${variable}="${content}"/" "${file}"
}
modifyVariableInFile ${@}
answered Jan 23 at 10:46
Alberto Salvia NovellaAlberto Salvia Novella
1105
Same answer as the accepted one, but ready to use in a script. In case someone finds it useful:
#! /bin/bash
# (GPL3+) Alberto Salvia Novella (es20490446e)
modifyVariableInFile () {
variable="${1}"
content="${2}"
file="${3}"
if [ ! -f "${file}" ]; then
echo "modifyVariableInFile: file doesn't exist: ${file}"
exit 1
fi
sed -i "s/^${variable}=.*/${variable}="${content}"/" "${file}"
}
modifyVariableInFile ${@}
answered Jan 23 at 10:46
Alberto Salvia NovellaAlberto Salvia Novella
1105
edited Jan 23 at 12:20
answered Jan 23 at 10:46
Alberto Salvia NovellaAlberto Salvia Novella
1105
answered Jan 23 at 10:46
Alberto Salvia NovellaAlberto Salvia Novella
1105
answered Jan 23 at 10:46
Alberto Salvia NovellaAlberto Salvia Novella
1105
1105
add a comment |
add a comment |
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1
Can you elaborate on what you have in mind? What's the goal and what have you tried so far?
– eblock
Jan 23 at 10:06
I believe the rest of the details would convolute the question.
– Alberto Salvia Novella
Jan 23 at 10:13
1
@AlbertoSalviaNovella I believe you should state what you are after. If you have multiple strings in a variable you probably want an array variable like
list=( element1 element2 element3 )– Valentin Bajrami
Jan 23 at 10:19
The variable I want to modify is already defined as a single string, but thanks for the point.
– Alberto Salvia Novella
Jan 23 at 10:43