README_bashlib.md

bashlib

Builds a bash script that can be sourced by other bash scripts to create OCRD-compliant CLI.

For example:

source `ocrd bashlib filename`
declare -A NAMESPACES MIMETYPES
eval NAMESPACES=( `ocrd bashlib constants NAMESPACES` )
echo ${NAMESPACES[page]}
eval MIMETYPE_PAGE=( `ocrd bashlib constants MIMETYPE_PAGE` )
echo $MIMETYPE_PAGE
eval MIMETYPES=( `ocrd bashlib constants EXT_TO_MIME` )
echo ${MIMETYPES[.jpg]}

• bashlib CLI
• bashlib API
• ocrd__raise
• ocrd__log
• ocrd__minversion
• ocrd__dumpjson
• ocrd__usage
• ocrd__parse_argv

bashlib CLI

See CLI usage

bashlib API

ocrd__raise

Raise an error and exit.

ocrd__log

Delegate logging to ocrd log

ocrd__minversion

Ensure minimum version

ocrd__dumpjson

Output ocrd-tool.json content verbatim.

Requires $OCRD_TOOL_JSON and $OCRD_TOOL_NAME to be set:

export OCRD_TOOL_JSON=/path/to/ocrd-tool.json
export OCRD_TOOL_NAME=ocrd-foo-bar

(Which you automatically get from ocrd__wrap.)

ocrd__show_resource

Output given resource file's content.

ocrd__list_resources

Output all resource files' names.

ocrd__usage

Print help on CLI usage.

ocrd__parse_argv

Parses arguments according to OCR-D CLI. In doing so, depending on the values passed to it, may delegate to …

• ocrd__raise and exit (if something went wrong)
• ocrd__usage and exit
• ocrd__dumpjson and exit
• ocrd__show_resource and exit
• ocrd__list_resources and exit
• ocrd validate tasks and return

Expects an associative array ("hash"/"dict") ocrd__argv to be predefined:

declare -A ocrd__argv=()

This will be filled by the parser along the following keys:

• overwrite: whether --overwrite is enabled
• profile: whether --profile is enabled
• profile_file: the argument of --profile-file
• log_level: the argument of --log-level
• mets_file: absolute path of the --mets argument
• working_dir: absolute path of the --working-dir argument or the parent of mets_file
• page_id: the argument of --page-id
• input_file_grp: the argument of --input-file-grp
• output_file_grp: the argument of --output-file-grp

Moreover, there will be an associative array params with the fully expanded runtime values of the ocrd-tool.json parameters.

ocrd__wrap

Parses an ocrd-tool.json for a specific tool (i.e. processor executable).

Delegates to …

• ocrd__parse_argv, creating the ocrd__argv associative array
• ocrd bashlib input-files, creating the data structures used by ocrd__input_file

Usage: ocrd__wrap PATH/TO/OCRD-TOOL.JSON EXECUTABLE ARGS

For example:

ocrd__wrap $SHAREDIR/ocrd-tool.json ocrd-olena-binarize "$@"
...

ocrd__input_file

(Requires ocrd__wrap to have been run first.)

Access information on the input files according to the parsed CLI arguments:

• their file url (or local file path)
• their file ID
• their mimetype
• their pageId
• their proposed corresponding outputFileId (generated from ${ocrd__argv[output__file_grp]} and input file ID)

Usage: ocrd__input_file NR KEY

For example:

pageId=`ocrd__input_file 3 pageId`

To be used in a loop over all selected pages:

for ((n=0; n<${#ocrd__files[*]}; n++)); do
    local in_fpath=($(ocrd__input_file $n url))
    local in_id=($(ocrd__input_file $n ID))
    local in_mimetype=($(ocrd__input_file $n mimetype))
    local in_pageId=($(ocrd__input_file $n pageId))
    local out_id=$(ocrd__input_file $n outputFileId)
    local out_fpath="${ocrd__argv[output_file_grp]}/${out_id}.xml

    # process $in_fpath to $out_fpath ...

    declare -a options
    if [ -n "$in_pageId" ]; then
        options=( -g $in_pageId )
    else
        options=()
    fi
    if [[ "${ocrd__argv[overwrite]}" == true ]];then
        options+=( --force )
    fi
    options+=( -G ${ocrd__argv[output_file_grp]}
               -m $MIMETYPE_PAGE -i "$out_id"
               "$out_fpath" )
    ocrd -l ${ocrd__argv[log_level]} workspace -d ${ocrd__argv[working_dir]} add "${options[@]}"

Note: If the --input-file-grp is multi-valued (N fileGrps separated by commas), then usage is similar:

• The function ocrd__input_file can be used, but its results will be lists (delimited by whitespace and surrounded by single quotes), e.g. [url]='file1.xml file2.xml' [ID]='id_file1 id_file2' [mimetype]='application/vnd.prima.page+xml image/tiff' ....
• Therefore its results should be encapsulated in a (non-associative) array variable and without extra quotes, e.g. in_file=($(ocrd__input_file 3 url)), or as shown above.
• This will yield the first fileGrp's results on index 0, which in bash will always be the same as if you referenced the array without index (so code does not need to be changed much), e.g. test -f $in_file which equals test -f ${in_file[0]}.
• Additional fileGrps will have to be fetched from higher indexes, e.g. test -f ${in_file[1]}.