file

Arguments

file-name

string, file name of the file to be opened

This function can not open files whose path has non-ascii UTF characters (accented, etc). In this case, mopen() must be used.

status

string, The status of the file to be opened

"new"

file must not exist new file (default)

"old"

file must already exists.

"unknown"

unknown status

"scratch"

file is to be deleted at end of session

access

string, The type of access to the file

"sequential"

sequential access (default)

"direct"

direct access. The next input argument recl is then mandatory.

format

string,

"formatted"

for a formatted file (default)

"unformatted"

binary record.

recl

integer,is the size of records in bytes when access="direct"

unit

integer, logical unit descriptor of the opened file

units

integer vector, logical unit descriptor of the opened files. Units 5 and 6 (%io) are reserved by the system for input and output devices.

typs

Character string vector, type (C or Fortran) of opened files.

nams

Character string vector, pathnames of opened files.

mod

file opening mode. Formed by three digits abc:

>Fortran files
a	0 stands for formatted and 1 for unformatted (binary)
b	0 stands for sequential access and 1 for direct access
c	0 stands for "new", 1 for "old", 2 for "scratch" and 3 for "unknown"
C files
a	1 stands for "r" (read), 2 stands for "w" (write) and 3 for "a" (append)
b	is 1 if file has been opened with a "+" (updating) mode
c	is 1 if file has been opened with a "b" (binary) mode

swap

automatic swap switch. swap=1 if automatic swap is on. swap is always 0 for Fortran files.

err

integer code returned if opening the file fails. If err is omitted, an error message is issued.

65	File already used
66	Too many files opened!
67	Unknown file format
240	The file already exists or directory write access denied.
241	The file does not exist or read access denied.

Description

file(…) selects a logical unit unit and manages the file file-name.

[unit [,err]]=file("open", file-name [,status] [,access [,recl]][,format])

allows to open a file with specified properties and to get the associated unit number unit. This unit number may be used for further actions on this file or as file descriptor in read, write, save, load function calls.

file("close", unit)

allows to close the file, or move the current file pointer.

file("rewind", unit)

puts the pointer at the beginning of the file.

file("backspace", unit)

puts the pointer at the beginning of last record.

file("last", unit)

puts the pointer after last record.

file()

returns the descriptors of the opened files.

To test whether a file whose unit is id is opened, file(id)~=[] may be used.

To close all user opened files (C or Fortran type), file("close",file()) may be used.

Examples

u=file("open",TMPDIR+"/foo","unknown")
for k=1:4
  a=rand(1,4)
  write(u,a)
end
file("rewind",u)
x=read(u,2,4)
file("close",u)
//
u1=file("open",TMPDIR+"/foo","unknown")
u2=mopen(TMPDIR+"/foo1","wb")
[units,typs,nams]=file()
file("close",u1);
mclose(u2);

See also

• isfile — checks whether argument is an existing file
• read — matrices read
• write — writes real numbers or strings in the console or in a formatted file
• mopen — opens files in Scilab
• save — Saves some chosen variables in a binary data file
• load — Loads some archived variables, a saved graphic figure, a library of functions
• uigetfile — dialog window to get a file(s) name(s), path and filter index

History