Tribblix: manual page: pathchk.1

PATHCHK(1) User Commands PATHCHK(1)

NAME

pathchk - check path names

SYNOPSIS

pathchk [-p] path...

DESCRIPTION

The pathchk command will check that one or more path names are valid
(that is, they could be used to access or create a file without
causing syntax errors) and portable (that is, no filename truncation
will result). More extensive portability checks are provided by the
-p option.

By default, pathchk will check each component of each path operand
based on the underlying file system. A diagnostic will be written for
each path operand that:

o is longer than PATH_MAX bytes.

o contains any component longer than NAME_MAX bytes in its
containing directory

o contains any component in a directory that is not
searchable

o contains any character in any component that is not valid
in its containing directory.

The format of the diagnostic message is not specified, but will
indicate the error detected and the corresponding path operand.

It will not be considered an error if one or more components of a
path operand do not exist as long as a file matching the path name
specified by the missing components could be created that does not
violate any of the checks specified above.

OPTIONS

The following option is supported:

-p
Instead of performing checks based on the underlying file
system, write a diagnostic for each path operand that:

o is longer than _POSIX_PATH_MAX bytes

o contains any component longer than _POSIX_NAME_MAX
bytes

o contains any character in any component that is not
in the portable filename character set.

OPERANDS

The following operand is supported:

path
A path to be checked.

USAGE

See largefile(7) for the description of the behavior of pathchk when
encountering files greater than or equal to 2 Gbyte ( 2^31 bytes).

EXAMPLES

Example 1: Using the pathchk command

To verify that all paths in an imported data interchange archive are
legitimate and unambiguous on the current system:

example% pax -f archive | sed -e '/ == .*/s///' | xargs pathchk
if [ $? -eq 0 ]
then
pax -r -f archive
else
echo Investigate problems before importing files.
exit 1
fi

To verify that all files in the current directory hierarchy could be
moved to any system conforming to the X/Open specification that also
supports the pax(1) command:

example% find . -print | xargs pathchk -p
if [ $? -eq 0 ]
then
pax -w -f archive .
else
echo Portable archive cannot be created.
exit 1
fi

To verify that a user-supplied path names a readable file and that
the application can create a file extending the given path without
truncation and without overwriting any existing file:

example% case $- in
*C*) reset="";;
*) reset="set +C"
set -C;;
esac
test -r "$path" && pathchk "$path.out" &&
rm "$path.out" > "$path.out"
if [ $? -ne 0 ]; then
printf "%s: %s not found or %s.out fails \
creation checks.\n" $0 "$path" "$path"
$reset # reset the noclobber option in case a trap
# on EXIT depends on it
exit 1
fi
$reset
PROCESSING < "$path" > "$path.out"

The following assumptions are made in this example:

1. PROCESSING represents the code that will be used by the
application to use $path once it is verified that
$path.out will work as intended.

2. The state of the noclobber option is unknown when this
code is invoked and should be set on exit to the state it
was in when this code was invoked. (The reset variable is
used in this example to restore the initial state.)

3. Note the usage of:

rm "$path.out" > "$path.out"

a.
The pathchk command has already verified, at this point,
that $path.out will not be truncated.

b.
With the noclobber option set, the shell will verify that
$path.out does not already exist before invoking rm.

c.
If the shell succeeded in creating $path.out, rm will
remove it so that the application can create the file again
in the PROCESSING step.

d.
If the PROCESSING step wants the file to exist already when
it is invoked, the:

rm "$path.out" > "$path.out"

should be replaced with:

> "$path.out"

which will verify that the file did not already exist, but
leave $path.out in place for use by PROCESSING.

ENVIRONMENT VARIABLES

See environ(7) for descriptions of the following environment
variables that affect the execution of pathchk: LANG, LC_ALL,
LC_CTYPE, LC_MESSAGES, and NLSPATH.

EXIT STATUS

The following exit values are returned:

0
All path operands passed all of the checks.

>0
An error occurred.

ATTRIBUTES