Pure bash program for auto-filling a template file with ENV variables The Next CEO of Stack Overflow'find' template for handling any fileBash to find all placeholder variables in a file and replace will real variablesapt alternative for proxy environment with bash shellBash script to replace substrings in a file with stringsSLOC Counter Script OptimizationLocating the Bash history file for a userDaemonizing shell scripts - MqSHBASH correct usage of single/double quotes when writing variables to filebash script - sed - template file processingBash function to find contents of a file with a certain extension
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Pure bash program for auto-filling a template file with ENV variables
The Next CEO of Stack Overflow'find' template for handling any fileBash to find all placeholder variables in a file and replace will real variablesapt alternative for proxy environment with bash shellBash script to replace substrings in a file with stringsSLOC Counter Script OptimizationLocating the Bash history file for a userDaemonizing shell scripts - MqSHBASH correct usage of single/double quotes when writing variables to filebash script - sed - template file processingBash function to find contents of a file with a certain extension
$begingroup$
Goal of Program
Consider a template file template.txt with double brace variables, intended to be replaced by values:
hello there MY_VAR1
some other stuff
some other stuff
foo: MY_VAR2
MY_VAR2 is the value of MY_VAR2
and assume you have defined and exported those variables:
export MY_VAR1=val1
export MY_VAR2=val2
we want a script fill_template such that fill_template template.txt produces:
hello there val1
some other stuff
some other stuff
foo: val2
val2 is the value of MY_VAR2
and which gives an appropriate error message if any of the required template variables are not defined.
Code for review
Here is working code for fill_template:
#!/bin/bash
if [[ ! -f $1 ]]; then
>&2 echo "Usage: $0 <filename>"
exit 1
fi
# Gather all the required template variables
vars=()
while IFS= read -r line; do
vars+=( "$line" )
done < <( awk 'match($0, / (.*) /, a) print a[1] ' "$1" | sort -u )
# Verify that all template variables are set and exported
missing=()
for var in "$vars[@]"; do
if [[ -z $!var+x ]]; then
missing+=( "$var" )
fi
done
if [[ $#missing[@] -gt 0 ]]; then
>&2 echo "The following required variables have not been set and exported:"
for var in "$missing[@]"; do
>&2 echo "$var"
done
exit 1
fi
# Dynamically construct the sed cmd to do the replacement
sed_cmd=
for var in "$vars[@]"; do
sed_cmd+="s/\\ *$var */$!var/g;"
done
sed -E "$sed_cmd" "$1"
Notes
- All comments welcome, from the high-level approach to nitpicks.
- Currently we assume there will be only one
TEMPLATE_VARper line
bash
asked 3 mins ago
JonahJonah
3,439717
$endgroup$
add a comment |
$begingroup$
Goal of Program
Consider a template file template.txt with double brace variables, intended to be replaced by values:
hello there MY_VAR1
some other stuff
some other stuff
foo: MY_VAR2
MY_VAR2 is the value of MY_VAR2
and assume you have defined and exported those variables:
export MY_VAR1=val1
export MY_VAR2=val2
we want a script fill_template such that fill_template template.txt produces:
hello there val1
some other stuff
some other stuff
foo: val2
val2 is the value of MY_VAR2
and which gives an appropriate error message if any of the required template variables are not defined.
Code for review
Here is working code for fill_template:
#!/bin/bash
if [[ ! -f $1 ]]; then
>&2 echo "Usage: $0 <filename>"
exit 1
fi
# Gather all the required template variables
vars=()
while IFS= read -r line; do
vars+=( "$line" )
done < <( awk 'match($0, / (.*) /, a) print a[1] ' "$1" | sort -u )
# Verify that all template variables are set and exported
missing=()
for var in "$vars[@]"; do
if [[ -z $!var+x ]]; then
missing+=( "$var" )
fi
done
if [[ $#missing[@] -gt 0 ]]; then
>&2 echo "The following required variables have not been set and exported:"
for var in "$missing[@]"; do
>&2 echo "$var"
done
exit 1
fi
# Dynamically construct the sed cmd to do the replacement
sed_cmd=
for var in "$vars[@]"; do
sed_cmd+="s/\\ *$var */$!var/g;"
done
sed -E "$sed_cmd" "$1"
Notes
- All comments welcome, from the high-level approach to nitpicks.
- Currently we assume there will be only one
TEMPLATE_VARper line
bash
asked 3 mins ago
JonahJonah
3,439717
$endgroup$
add a comment |
$begingroup$
Goal of Program
Consider a template file template.txt with double brace variables, intended to be replaced by values:
hello there MY_VAR1
some other stuff
some other stuff
foo: MY_VAR2
MY_VAR2 is the value of MY_VAR2
and assume you have defined and exported those variables:
export MY_VAR1=val1
export MY_VAR2=val2
we want a script fill_template such that fill_template template.txt produces:
hello there val1
some other stuff
some other stuff
foo: val2
val2 is the value of MY_VAR2
and which gives an appropriate error message if any of the required template variables are not defined.
Code for review
Here is working code for fill_template:
#!/bin/bash
if [[ ! -f $1 ]]; then
>&2 echo "Usage: $0 <filename>"
exit 1
fi
# Gather all the required template variables
vars=()
while IFS= read -r line; do
vars+=( "$line" )
done < <( awk 'match($0, / (.*) /, a) print a[1] ' "$1" | sort -u )
# Verify that all template variables are set and exported
missing=()
for var in "$vars[@]"; do
if [[ -z $!var+x ]]; then
missing+=( "$var" )
fi
done
if [[ $#missing[@] -gt 0 ]]; then
>&2 echo "The following required variables have not been set and exported:"
for var in "$missing[@]"; do
>&2 echo "$var"
done
exit 1
fi
# Dynamically construct the sed cmd to do the replacement
sed_cmd=
for var in "$vars[@]"; do
sed_cmd+="s/\\ *$var */$!var/g;"
done
sed -E "$sed_cmd" "$1"
Notes
- All comments welcome, from the high-level approach to nitpicks.
- Currently we assume there will be only one
TEMPLATE_VARper line
bash
asked 3 mins ago
JonahJonah
3,439717
$endgroup$
Goal of Program
Consider a template file template.txt with double brace variables, intended to be replaced by values:
hello there MY_VAR1
some other stuff
some other stuff
foo: MY_VAR2
MY_VAR2 is the value of MY_VAR2
and assume you have defined and exported those variables:
export MY_VAR1=val1
export MY_VAR2=val2
we want a script fill_template such that fill_template template.txt produces:
hello there val1
some other stuff
some other stuff
foo: val2
val2 is the value of MY_VAR2
and which gives an appropriate error message if any of the required template variables are not defined.
Code for review
Here is working code for fill_template:
#!/bin/bash
if [[ ! -f $1 ]]; then
>&2 echo "Usage: $0 <filename>"
exit 1
fi
# Gather all the required template variables
vars=()
while IFS= read -r line; do
vars+=( "$line" )
done < <( awk 'match($0, / (.*) /, a) print a[1] ' "$1" | sort -u )
# Verify that all template variables are set and exported
missing=()
for var in "$vars[@]"; do
if [[ -z $!var+x ]]; then
missing+=( "$var" )
fi
done
if [[ $#missing[@] -gt 0 ]]; then
>&2 echo "The following required variables have not been set and exported:"
for var in "$missing[@]"; do
>&2 echo "$var"
done
exit 1
fi
# Dynamically construct the sed cmd to do the replacement
sed_cmd=
for var in "$vars[@]"; do
sed_cmd+="s/\\ *$var */$!var/g;"
done
sed -E "$sed_cmd" "$1"
Notes
- All comments welcome, from the high-level approach to nitpicks.
- Currently we assume there will be only one
TEMPLATE_VARper line
bash
bash
asked 3 mins ago
JonahJonah
3,439717
asked 3 mins ago
JonahJonah
3,439717
asked 3 mins ago
JonahJonah
3,439717
asked 3 mins ago
JonahJonah
3,439717
asked 3 mins ago
JonahJonah
3,439717
3,439717
add a comment |
add a comment |
0
active
oldest
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