10-11-2001
Is appending to file with >> interruptable?
I have a script1.ksh that calls another script2.ksh and redirects and appends script2.ksh's output to a file:
#script1.ksh
...
script2.ksh >> outfile
...
#script2.ksh
...
echo value1 value2 value3 ...valuen
....
Suppose I have many script1.ksh processes running at the same
time. Is it possible that file "outfile" can be corrupted if multiple
scripts/processes are writing to it at the same time?
If not corrupted, is it possible that the values written by echo
are interrupted such that the output values are interleaved with
values from the other processes?
Perhaps a simpler way of asking this question is whether the
redirection operators > and >> are atomic (ie non-interruptable)?
Thanks again,
ragtopgeek
PS - Sorry about the verbosity of my question, but you can thank
the public schools for that.
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LEARN ABOUT OPENSOLARIS
let
let(1) User Commands let(1)
NAME
let - shell built-in function to evaluate one or more arithmetic expressions
SYNOPSIS
ksh
let arg...
ksh93
let [expr...]
DESCRIPTION
ksh
Each arg is a separate arithmetic expression to be evaluated.
ksh93
let evaluates each expr in the current shell environment as an arithmetic expression using ANSI C syntax. Variables names are shell vari-
ables and they are recursively evaluated as arithmetic expressions to get numerical values. let has been made obsolete by the ((...)) syn-
tax of ksh93(1) which does not require quoting of the operators to pass them as command arguments.
EXIT STATUS
ksh
ksh returns the following exit values:
0 The value of the last expression is non-zero.
1 The value of the last expression is zero.
ksh93
ksh93 returns the following exit values:
0 The last expr evaluates to a non-zero value.
>0 The last expr evaluates to 0 or an error occurred.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWcsu |
+-----------------------------+-----------------------------+
SEE ALSO
ksh(1), ksh93(1), set(1), typeset(1), attributes(5)
SunOS 5.11 2 Nov 2007 let(1)