NAME

touch − update date last modified of a file

SYNOPSIS

touch [ −c ] [ −f ] file ...

DESCRIPTION

Touch attempts to set the modified date of each file. If the file exists, this is done by reading a character from the file and writing it back.

Touch is valuable when used in conjunction with make(1), where, for instance, you might want to force a complete rebuild of a program composed of many pieces.  In such a case, you might type, for example:

% touch  ∗.c
% make

and the make would then see that all the .c files were more up to date than all the corresponding .o files, and would start the build from scratch. 

OPTIONS

−cDo not attempt to create a file if it does not exist. 

−fAttempt to force the touch in spite of read and write permissions on a file.

Sun Release 3.0β  —  Last change: 14 June 1983