Linux

Googling the terms: 'itstat' and 'resolution' together didn't return any results. I think you must be following some internal documentation about an internally developed utility.

Find more details, and I'll try to help you out.

D

Actually I tried the same thing.
Is there any way to create a perl script that will display the file names and resolutions of jpeg files in a linux environment?

DESCRIPTION

These functions return information about the specified file. You do not need any access rights to the file to get this information but you need search rights to all directories named in the path leading to the file.

stat stats the file pointed to by file_name and fills in buf.

lstat is identical to stat, except in the case of a symbolic link, where the link itself is stat-ed, not the file that it refers to.

fstat is identical to stat, only the open file pointed to by filedes (as returned by open(2)) is stat-ed in place of file_name.

They all return a stat structure, which contains the following fields:
{tabled display won't look right: }
struct stat {
dev_t st_dev; /* device */
ino_t st_ino; /* inode */
mode_t st_mode; /* protection */
nlink_t st_nlink; /* number of hard links */
uid_t st_uid; /* user ID of owner */
gid_t st_gid; /* group ID of owner */
dev_t st_rdev; /* device type (if inode device) */
off_t st_size; /* total size, in bytes */
blksize_t st_blksize; /* blocksize for filesystem I/O */
blkcnt_t st_blocks; /* number of blocks allocated */
time_t st_atime; /* time of last access */
time_t st_mtime; /* time of last modification */
time_t st_ctime; /* time of last change */
};


from:
http://www.die.net/doc/linux/man/man2/lstat.2.html

search results from google:
http://www.google.ca/linux?hl=en&q=lstat&btnG=Search&meta=

since I don't know perl, can't help with the script itself, but these should give some data for working with the lstat tool.

for the last poster.
which lib / module for perl will read /write image files?

I know that it can be done from bash, and by building a c or c++ program, but don't know perl to know if it can even read image files.

thank you Jaqui
this is pointing me in the right direction.
Just out of curiosity, can you show me how the function would look in bash or c?

Given your requirements and the assumption that a program called itstat exists with that output, this will do the trick:

ls|while read line
do
resolution=`itstat|grep Resolution|cut -f2 -d:`
echo "$line: $resolution"
done

If you really need the format as you state (not really that readable for 50 entries) replace the echo line with this:

echo "$line: $resolution \c"

and add another "echo" at the very end.


Gary

This sounds like some sort of class project with where you are to write a small perl script that uses a make believe command line utility. If this is the case the perl script would look like this:

open (CMD, "itstat |");

while (<CMD&gt {
if (m/File:/) {
s/^\s*File:\s*//;
$file = $_;
} elsif (m/Resolution:/) {
s/^\s*Resolution:\s*//;
$res = $_;
print $file, ": ", $res, "\n";
}

close(CMD);

This will accomplish what you need, without error checking, however, and because it is not using the FileHandle module or the my declaration it is not cleanly written.