NeoMutt's format strings can contain embedded if-then-else conditions. They are of the form:
%?VAR?TRUE&FALSE?
If the variable “VAR” has a value greater than zero, print the “TRUE” string, otherwise print the “FALSE” string.
e.g.
%?S?Size: %S&Empty?
Which can be read as:
if (%S > 0) { print "Size: %S" } else { print "Empty" }
These conditions are useful, but in NeoMutt they cannot be nested within one another. This feature uses the notation
%<VAR?TRUE&FALSE> and allows them to be nested.
The
%<...> notation was used to format the current local time. but that's not really very useful since NeoMutt has no means of refreshing the screen periodically.
A simple nested condition might be: (Some whitespace has been introduced for clarity)
%<x? %<y? XY & X > & %<y? Y & NONE > > Conditions
%<y? XY & X > x>0
XY x>0,y>0
X x>0,y=0
%<x? %<y? XY & X > & %<y? Y & NONE > > Conditions
%<y? Y & NONE > x=0
Y x=0,y>0
NONE x=0,y=0
Equivalent to:
if (x > 0) {
if (y > 0) {
print 'XY'
} else {
print 'X'
}
} else {
if (y > 0) {
print 'Y'
} else {
print 'NONE'
}
}
Examples:
set index_format='%4C %Z %{%b %d} %-25.25n %s%> %<M?%M Msgs &%<l?%l Lines&%c Bytes>>'
if a thread is folded display the number of messages (%M)
else if we know how many lines in the message display lines in message (%l)
else display the size of the message in bytes (%c)
set index_format='%4C %Z %{%b %d} %-25.25n %<M?[%M] %s&%s%* %<l?%l&%c>>'
if a thread is folded display the number of messages (%M) and the subject (%s)
else if we know how many lines are in the message display subject (%s) and the lines in message (%l)
else display the subject (%s) and the size of the message in bytes (%c)
If you wish to use angle brackets
< > in a nested condition, then it's necessary to escape them, e.g.
set index_format='%<M?\<%M\>&%s>'
The “nested-if” feature doesn't have any config of its own. It modifies the behavior of the format strings.
# Example NeoMutt config file for the nested-if feature. # This feature uses the format: '%<VAR?TRUE&FALSE>' for conditional # format strings that can be nested. # Example 1 # if a thread is folded # display the number of messages (%M) # else if we know how many lines in the message # display lines in message (%l) # else display the size of the message in bytes (%c) set index_format='%4C %Z %{%b %d} %-25.25n %s%> %<M?%M Msgs &%<l?%l Lines&%c Bytes>>' # Example 2 # if a thread is folded # display the number of messages (%M) # display the subject (%s) # else if we know how many lines in the message # display lines in message (%l) # else # display the size of the message in bytes (%c) set index_format='%4C %Z %{%b %d} %-25.25n %<M?[%M] %s&%s%* %<l?%l&%c>>' # vim: syntax=neomuttrc
