[%CFEngine_function_prototype(filename, optional_maxbytes)%]
Description:
Returns the first maxbytes
bytes from file filename
.
maxbytes
is optional, if specified, only the first maxbytes
bytes are read from filename
.
When maxbytes
is 0
or not specified, the whole file will be read (but see Notes below).
[%CFEngine_function_attributes(filename, optional_maxbytes)%]
Example:
Prepare:
[%CFEngine_include_snippet(readfile.cf, #+begin_src prep, .*end_src)%]
Run:
[%CFEngine_include_snippet(readfile.cf, #+begin_src cfengine3, .*end_src)%]
Output:
[%CFEngine_include_snippet(readfile.cf, #+begin_src\s+example_output\s, .end_src)%]
Notes:
To reliably read files located within /proc or /sys directories,
maxsize
has to be set to 0
.
At the moment, only 4095 bytes can fit into a string variable. This limitation may be removed in the future. If this should happen, a warning will be printed.
If you request more bytes than CFEngine can read into a string
variable (e.g. 999999999
), a warning will also be printed.
If either because you specified a large value, or you specified 0
,
more bytes are read than will fit in a string, the string is
truncated to the maximum.
On Windows, the file will be read in text mode, which means that CRLF line endings will be converted to LF line endings in the resulting variable. This can make the variable length shorter than the size of the file being read.
History: Warnings about the size limit and the special 0
value were introduced in 3.6.0