Difference between revisions of "Bash"
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You can probably get rid of the ''declare'' line at the bottom - this just ensures that ''TMOUT'' cannot subsequently be modified. | You can probably get rid of the ''declare'' line at the bottom - this just ensures that ''TMOUT'' cannot subsequently be modified. | ||
| + | |||
| + | == Remove 'Graph this data ...' footnote from logon message == | ||
| + | Edit /usr/share/pyshared/landscape/sysinfo/landscapelink.py and comment out the 3 lines starting '''self._sysinfo.add_footnote''' | ||
Latest revision as of 14:06, 9 November 2012
Contents
Changing IFS to line endings only
OLDIFS=$IFS IFS=$'\x0a'
or
OLDIFS=$IFS IFS=$'\n'
History Manipulation
To repeat a previous command or subsection of a previous command, optionally performing some kind of modification to it, run event[:word][:modifier][:modifier]....
Event Designators
| Designator | Meaning |
|---|---|
| !! | The previous command. |
| !n | Command number n in the history list. |
| !-n | The nth preceding command. |
| !string | The most recent command line that started with string. |
| !?string[?] | The most recent command that contained string. The last ? is optional. |
| !# | The current command (as you have it typed so far). |
| !{event} | The event is an event designator. The braces isolate event from the surrounding text. For example, !{-3}3 is the third most recently executed command followed by a 3. |
Word Designators
| Designator | Meaning |
|---|---|
| n | The nth word. Word 0 is normally the command name. |
| ^ | The first word (after the command name). |
| $ | The last word. |
| m-n | All words from word number m through word number n; m defaults to 0 if you omit it (0-n). |
| n* | All words from word number n through the last word. |
| * | All words except the command name. The same as 1*. |
| % | The word matched by the most recent ?string? search. |
Modifiers
| Designator | Meaning |
|---|---|
| e (extension) | Removes all but the filename extension |
| h (head) | Removes the last part of a pathname |
| p (print-not) | Displays the command, but does not execute it |
| q (quote) | Quotes the substitution to prevent further substitutions on it |
| r (root) | Removes the filename extension |
| [g]s!old!new[!] (substitute) | Substitutes new for old (eg. !!:0:s!ch!lm runs the first word of the previous command, substituting lm for ch in the string). The optional g replaces all occurrences of old rather than just the first one. The trailing ! is optional if the command is immediately followed by a RETURN. |
| t (tail) | Removes all elements of a pathname except the last |
| x | Like q but quotes each word in the substitution individually |
Force autologout of root and other privileged account shells after inactivity
Add to /etc/bash.bashrc (not /etc/profile, or it will only be set when running su - and not su):
if [ `id -u` -lt 500 ]; then
# Override console timeout for root and other system users
TMOUT_ROOT=3600
if [ -n "$TMOUT" ]; then
if [ "$TMOUT" -eq "0" -o "$TMOUT" -gt "$TMOUT_ROOT" ]; then
TMOUT=$TMOUT_ROOT
fi
else
TMOUT=$TMOUT_ROOT
fi
fi
type declare > /dev/null 2>&1 && declare -r TMOUT
You can probably get rid of the declare line at the bottom - this just ensures that TMOUT cannot subsequently be modified.
Remove 'Graph this data ...' footnote from logon message
Edit /usr/share/pyshared/landscape/sysinfo/landscapelink.py and comment out the 3 lines starting self._sysinfo.add_footnote
