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45 lines
969 B
Markdown
45 lines
969 B
Markdown
# String Operators
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## RegEx
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This uses golangs native regex functions under the hood - See https://github.com/google/re2/wiki/Syntax for the supported syntax.
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## String blocks, bash and newlines
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Bash is notorious for chomping on precious trailing newline characters, making it tricky to set strings with newlines properly. In particular, the `$( exp )` _will trim trailing newlines_.
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For instance to get this yaml:
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```
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a: |
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cat
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```
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Using `$( exp )` wont work, as it will trim the trailing new line.
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```
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m=$(echo "cat\n") yq e -n '.a = strenv(m)'
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a: cat
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```
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However, using printf works:
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```
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printf -v m "cat\n" ; m="$m" yq e -n '.a = strenv(m)'
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a: |
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cat
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```
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As well as having multiline expressions:
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```
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m="cat
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" yq e -n '.a = strenv(m)'
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a: |
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cat
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```
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Similarly, if you're trying to set the content from a file, and want a trailing new line:
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```
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IFS= read -rd '' output < <(cat my_file)
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output=$output ./yq e '.data.values = strenv(output)' first.yml
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```
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