Sha1
Calculate a SHA1 hash of an object
Description
Calculate a SHA1 hash of an object. The main difference with
digest(x, algo = "sha1") is that sha1() will give the same hash on
32-bit and 64-bit systems. Note that the results depends on the setting
of digits and zapsmall when handling floating point numbers. The
current defaults keep digits and zapsmall as large as possible while
maintaining the same hash on 32 bit and 64 bit systems.
Usage
sha1(x, digits = 14, zapsmall = 7, ..., algo = "sha1")
## S3 method for class 'numeric'
sha1(x, digits = 14, zapsmall = 7, ..., algo = "sha1")
## S3 method for class 'complex'
sha1(x, digits = 14, zapsmall = 7, ..., algo = "sha1")
## S3 method for class 'Date'
sha1(x, digits = 14, zapsmall = 7, ..., algo = "sha1")
## S3 method for class 'matrix'
sha1(x, digits = 14, zapsmall = 7, ..., algo = "sha1")
## S3 method for class 'data.frame'
sha1(x, digits = 14, zapsmall = 7, ..., algo = "sha1")
## S3 method for class 'array'
sha1(x, digits = 14, zapsmall = 7, ..., algo = "sha1")
## S3 method for class 'list'
sha1(x, digits = 14, zapsmall = 7, ..., algo = "sha1")
## S3 method for class 'pairlist'
sha1(x, digits = 14, zapsmall = 7, ..., algo = "sha1")
## S3 method for class 'POSIXlt'
sha1(x, digits = 14, zapsmall = 7, ..., algo = "sha1")
## S3 method for class 'POSIXct'
sha1(x, digits = 14, zapsmall = 7, ..., algo = "sha1")
## S3 method for class 'anova'
sha1(x, digits = 4, zapsmall = 7, ..., algo = "sha1")
## S3 method for class 'function'
sha1(x, digits = 14, zapsmall = 7, ..., algo = "sha1")
## S3 method for class 'formula'
sha1(x, digits = 14, zapsmall = 7, ..., algo = "sha1")
## S3 method for class ''(''
sha1(...)
sha1_digest(x, digits = 14, zapsmall = 7, ..., algo = "sha1")
## S3 method for class 'NULL'
sha1(...)
## S3 method for class 'name'
sha1(...)
sha1_attr_digest(x, digits = 14, zapsmall = 7, ..., algo = "sha1")
## S3 method for class 'call'
sha1(...)
## S3 method for class 'character'
sha1(...)
## S3 method for class 'factor'
sha1(...)
## S3 method for class 'integer'
sha1(...)
## S3 method for class 'logical'
sha1(...)
## S3 method for class 'raw'
sha1(...)
Arguments
x |
the object to calculate the SHA1 |
digits |
the approximate number of significant digits in base 10. Will be converted to a base 16 equivalent. Defaults to digits = 14, except for sha1.anova where digits = 4 |
zapsmall |
the approximate negative magnitude of the smallest relevant digit. Will be converted to a base 2 equivalent. Values smaller than this number are equivalent to 0. Defaults to zapsmall = 7 |
... |
If it is the only defined argument, passed to another sha1 method. If other arguments exist, see Details for usage. |
algo |
The hashing algoritm to be used by digest. Defaults to "sha1" |
Details
sha1_digest() is a convenience function for objects where attributes
cannot be added to apply the digest() function to its arguments.
sha1_attr_digest() is a convenience function for objects where objects
can be added to generate the hash. If generating hashes for objects in
other packages, one of these two functions is recommended for use
(typically, sha1_attr_digest()).
Extra arguments:
environment: An optional extra argument for sha1.function and
sha1.formula should be TRUE, FALSE or missing. sha1.function and
sha1.formula will ignore the enviroment of the function only when
environment = FALSE.
Note
sha1 gained an algo argument since version 0.6.15. This allows
sha1() to use all hashing algoritms available in digest(). The
hashes created with sha1(x) from digest >= 0.6.15 are identical to
sha1(x) from digest \<= 0.6.14. The only exceptions are hashes created
with sha1(x, algo = "sha1"), they will be different starting from
digest 0.6.15
Until version 0.6.22, sha1 ignored the attributes of the object for
some classes. This was fixed in version 0.6.23. Use
options(sha1PackageVersion = "0.6.22") to get the old behaviour.
Version 0.6.24 and later ignore attributes named srcref.
Author(s)
Thierry Onkelinx