R: List Objects and their Structure

ls.str {utils} | R Documentation

## List Objects and their Structure

### Description

`ls.str` and `lsf.str` are variations of `ls` applying `str()` to each matched name: see section Value.

### Usage

    ls.str(pos = -1, name, envir, all.names = FALSE,
           pattern, mode = "any")

    lsf.str(pos = -1, envir, ...)

    ## S3 method for class 'ls_str'
    print(x, max.level = 1, give.attr = FALSE, ...,
          digits = max(1, getOption("str")$digits.d))

### Arguments

`pos` | integer indicating `search` path position, or `-1` for the current environment.
`name` | optional name indicating `search` path position, see `ls`.
`envir` | environment to use, see `ls`.
`all.names` | logical indicating if names which begin with a `.` are omitted; see `ls`.
`pattern` | a regular expression passed to `ls`. Only names matching `pattern` are considered.
`max.level` | maximal level of nesting which is applied for displaying nested structures, e.g., a list containing sub lists. Default 1: Display only the first nested level.
`give.attr` | logical; if `TRUE` (default), show attributes as sub structures.
`mode` | character specifying the `mode` of objects to consider. Passed to `exists` and `get`.
`x` | an object of class `"ls_str"`.
`...` | further arguments to pass. `lsf.str` passes them to `ls.str` which passes them on to `ls`. The (non-exported) print method `print.ls_str` passes them to `str`.
`digits` | the number of significant digits to use for printing.

### Value

`ls.str` and `lsf.str` return an object of class `"ls_str"`, basically the character vector of matching names (functions only for `lsf.str`), similarly to `ls`, with a `print()` method that calls `str()` on each object.

### Author(s)

Martin Maechler

### See Also

`str`, `summary`, `args`.

### Examples

    require(stats)

    lsf.str()  #- how do the functions look like which I am using?
    ls.str(mode = "list")   #- what are the structured objects I have defined?

    ## create a few objects
    example(glm, echo = FALSE)
    ll <- as.list(LETTERS)
    print(ls.str(), max.level = 0)# don't show details

    ## which base functions have "file" in their name ?
    lsf.str(pos = length(search()), pattern = "file")

    ## demonstrating that  ls.str() works inside functions
    ## ["browser/debug mode"]:
    tt <- function(x, y = 1) { aa <- 7; r <- x + y; ls.str() }
    (nms <- sapply(strsplit(capture.output(tt(2))," *: *"), `[`, 1))
    stopifnot(nms == c("aa", "r","x","y"))

[Package utils version 4.0.5 Index]