12-11-2012
Not really, no. There is no seamless 'insert' operation for a file. To add extra data to the middle of a file, you must rewrite all the data that comes after it. That is why inserting data is so complicated, you never really do so.
The usual solutions for doing it all in one step, ed or sed -i, still use a temp file in many implementations.
So, since your records aren't fixed-width, the answer is no. If they were fixed-width, you could change any record without changing the length of the line, making it more possible, but fixed-width records are a difficult thing to handle in shell!
Last edited by Corona688; 12-11-2012 at 12:09 PM..
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LEARN ABOUT DEBIAN
bcron-update
bcron-update(8) System Manager's Manual bcron-update(8)
NAME
bcron-update - Update system crontabs.
SYNOPSIS
bcron-update path [ path ... ]
DESCRIPTION
bcron-update polls the named files or directories periodically to see if there are any new, changed, or removed files. When it detects
changes, it mirrors those changes into the crontab spool directory. bcron-update runs as root in order to be able to read system files
that would potentially be unreadable otherwise.
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letters ('a'-'z', 'A'-'Z'), digits ('0'-'9'), underscores ('_'), and hyphens ('-').
EXAMPLES
To mirror modern vixie-cron's behavior, use:
bcron-update /etc/crontab /etc/cron.d
ENVIRONMENT
BCRON_SPOOL
The spool directory for bcron. Defaults to /var/spool/cron.
BCRON_USER
After writing files and before moving them into their final location, bcron-update changes the ownership of the file to this user so
that bcron-sched can read them.
SEE ALSO
bcron-sched(8)
DIAGNOSTICS
bcron-update outputs three different kinds of messages about actions it is taking.
Rescanning /etc/cron.d
The named directory has been modified, and will be scanned to determine what files have been added or deleted.
-/etc/cron.d/oldfile
The named file no longer exists and will be removed from the spool.
+/etc/cron.d/newfile
The named file was either created or modified since the last scan, and will be copied into the spool.
AUTHOR
Bruce Guenter <bruceg@em.ca>
bcron-update(8)