Skip to contents

Call ExifTool from R

Source: R/exif_read.R
exif_call.Rd

Uses system2() to run a basic call to exiftool.

Usage

exif_call(
  args = NULL,
  path = NULL,
  stdout = TRUE,
  quiet = FALSE,
  ...,
  config_file = NULL,
  common_args = NULL
)

exif_version(quiet = TRUE)

Arguments

args

Character vector of arguments, each written in same form as you would if writing them on the command line (e.g. "-n" or "-csv")

path

A character vector giving one or more file paths.

stdout

Where output to stdout should be sent. If TRUE (the default), the output is captured in a character vector. For other options, see the help file for system2, the function to which this argument's value gets passed along.

quiet

Use FALSE to display diagnostic information. Default value is FALSE.

...

Additional arguments to be passed to system2().

config_file

Path to a config file of the format expected by Exiftool's command line -config option. (See Details for an explanation of why this one option cannot be passed directly to args via the -config argument.)

common_args

A character vector of arguments to be applied to all executed commands when the Exiftool -execute option is being used. (See Details for an explanation of why this option cannot be passed directly to args via -common_args argument.)

Value

The standard output as a character vector.

Details

For examples of the command-line calls to ExifTool (all of which can be reproduced by calls to exif_call), see https://exiftool.org/examples.html.

Under the hood, exif_call() writes the options in args to a text file and then calls Exiftool, passing that text file's contents to Exiftool via its -@ ARGFILE option. -config and -common_args are the two options that may not be used in such a -@ ARGFILE, so we handle that option separately using exif_call()'s config_file argument.

Examples

if (FALSE) { # \dontrun{
## Find local ExifTool version using exif_version() or exif_call()
exif_version()
exif_call(args = "-ver")

## Make temporary copies of a couple jpeg files
tmpdir <- tempdir()
src_files <- dir(system.file(package = "exiftoolr", "images"),
                 full.names = TRUE)
files <- file.path(tmpdir, basename(src_files))
file.copy(src_files, files)

## Both of the following extract the same tags:
exif_read(files, tags = c("filename", "imagesize"))
exif_call(args = c("-n", "-j", "-q", "-filename", "-imagesize"),
          path = files)

## Set value of a new "Artist" field in photo's metadata
file1 <- files[1]
exif_read(file1, tags = "artist")
exif_call(path = file1, args = "-Artist=me")
exif_read(file1, tags = "artist")

## Remove all but a few essential fields
length(exif_read(file1))
exif_call(path = file1, args = "-all=")
length(exif_read(file1))
exif_read(file1)

## Clean up
unlink(files)
} # }