github.com/Racer159/jackal@v0.32.7-0.20240401174413-0bd2339e4f2e/docs/2-the-jackal-cli/100-cli-commands/jackal_tools_yq_eval.md

# jackal tools yq eval
<!-- Auto-generated by hack/gen-cli-docs.sh -->

(default) Apply the expression to each document in each yaml file in sequence

## Synopsis

yq is a portable command-line data file processor (https://github.com/mikefarah/yq/) 
See https://mikefarah.gitbook.io/yq/ for detailed documentation and examples.

# Evaluate Sequence ##
This command iterates over each yaml document from each given file, applies the 
expression and prints the result in sequence.

```
jackal tools yq eval [expression] [yaml_file1]... [flags]
```

## Examples

```

# Reads field under the given path for each file
jackal tools yq e '.a.b' f1.yml f2.yml 

# Prints out the file
jackal tools yq e sample.yaml 

# Pipe from STDIN
# use '-' as a filename to pipe from STDIN
cat file2.yml | jackal tools yq e '.a.b' file1.yml - file3.yml

# Creates a new yaml document
# Note that editing an empty file does not work.
jackal tools yq e -n '.a.b.c = "cat"' 

# Update a file inplace
jackal tools yq e '.a.b = "cool"' -i file.yaml 

```

## Options

```
  -h, --help   help for eval
```

## Options inherited from parent commands

```
  -C, --colors                        force print with colors
      --csv-auto-parse                parse CSV YAML/JSON values (default true)
      --csv-separator char            CSV Separator character (default ,)
  -e, --exit-status                   set exit status if there are no matches or null or false is returned
      --expression string             forcibly set the expression argument. Useful when yq argument detection thinks your expression is a file.
      --from-file string              Load expression from specified file.
  -f, --front-matter string           (extract|process) first input as yaml front-matter. Extract will pull out the yaml content, process will run the expression against the yaml content, leaving the remaining data intact
      --header-preprocess             Slurp any header comments and separators before processing expression. (default true)
  -I, --indent int                    sets indent level for output (default 2)
  -i, --inplace                       update the file in place of first file given.
  -p, --input-format string           [auto|a|yaml|y|json|j|props|p|csv|c|tsv|t|xml|x|base64|uri|toml|lua|l] parse format for input. (default "auto")
      --lua-globals                   output keys as top-level global variables
      --lua-prefix string             prefix (default "return ")
      --lua-suffix string             suffix (default ";\n")
      --lua-unquoted                  output unquoted string keys (e.g. {foo="bar"})
  -M, --no-colors                     force print with no colors
  -N, --no-doc                        Don't print document separators (---)
  -0, --nul-output                    Use NUL char to separate values. If unwrap scalar is also set, fail if unwrapped scalar contains NUL char.
  -n, --null-input                    Don't read input, simply evaluate the expression given. Useful for creating docs from scratch.
  -o, --output-format string          [auto|a|yaml|y|json|j|props|p|csv|c|tsv|t|xml|x|base64|uri|toml|shell|s|lua|l] output format type. (default "auto")
  -P, --prettyPrint                   pretty print, shorthand for '... style = ""'
      --properties-array-brackets     use [x] in array paths (e.g. for SpringBoot)
      --properties-separator string   separator to use between keys and values (default " = ")
  -s, --split-exp string              print each result (or doc) into a file named (exp). [exp] argument must return a string. You can use $index in the expression as the result counter.
      --split-exp-file string         Use a file to specify the split-exp expression.
      --string-interpolation          Toggles strings interpolation of \(exp) (default true)
      --tsv-auto-parse                parse TSV YAML/JSON values (default true)
  -r, --unwrapScalar                  unwrap scalar, print the value with no quotes, colors or comments. Defaults to true for yaml (default true)
  -v, --verbose                       verbose mode
      --xml-attribute-prefix string   prefix for xml attributes (default "+@")
      --xml-content-name string       name for xml content (if no attribute name is present). (default "+content")
      --xml-directive-name string     name for xml directives (e.g. <!DOCTYPE thing cat>) (default "+directive")
      --xml-keep-namespace            enables keeping namespace after parsing attributes (default true)
      --xml-proc-inst-prefix string   prefix for xml processing instructions (e.g. <?xml version="1"?>) (default "+p_")
      --xml-raw-token                 enables using RawToken method instead Token. Commonly disables namespace translations. See https://pkg.go.dev/encoding/xml#Decoder.RawToken for details. (default true)
      --xml-skip-directives           skip over directives (e.g. <!DOCTYPE thing cat>)
      --xml-skip-proc-inst            skip over process instructions (e.g. <?xml version="1"?>)
      --xml-strict-mode               enables strict parsing of XML. See https://pkg.go.dev/encoding/xml for more details.
```

## SEE ALSO

* [jackal tools yq](jackal_tools_yq.md)	 - yq is a lightweight and portable command-line data file processor.