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list_safe_reset_next(9) [centos man page]

LIST_SAFE_RESET_NEXT(9) 					    Data Types						   LIST_SAFE_RESET_NEXT(9)

list_safe_reset_next - reset a stale list_for_each_entry_safe loop SYNOPSIS
list_safe_reset_next(pos, n, member); ARGUMENTS
pos the loop cursor used in the list_for_each_entry_safe loop n temporary storage used in list_for_each_entry_safe member the name of the list_struct within the struct. DESCRIPTION
list_safe_reset_next is not safe to use in general if the list may be modified concurrently (eg. the lock is dropped in the loop body). An exception to this is if the cursor element (pos) is pinned in the list, and list_safe_reset_next is called after re-taking the lock and before completing the current iteration of the loop body. COPYRIGHT
Kernel Hackers Manual 3.10 June 2014 LIST_SAFE_RESET_NEXT(9)

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foreach(n)						       Tcl Built-In Commands							foreach(n)


foreach - Iterate over all elements in one or more lists SYNOPSIS
foreach varname list body foreach varlist1 list1 ?varlist2 list2 ...? body _________________________________________________________________ DESCRIPTION
The foreach command implements a loop where the loop variable(s) take on values from one or more lists. In the simplest case there is one loop variable, varname, and one list, list, that is a list of values to assign to varname. The body argument is a Tcl script. For each element of list (in order from first to last), foreach assigns the contents of the element to varname as if the lindex command had been used to extract the element, then calls the Tcl interpreter to execute body. In the general case there can be more than one value list (e.g., list1 and list2), and each value list can be associated with a list of loop variables (e.g., varlist1 and varlist2). During each iteration of the loop the variables of each varlist are assigned consecutive values from the corresponding list. Values in each list are used in order from first to last, and each value is used exactly once. The total number of loop iterations is large enough to use up all the values from all the value lists. If a value list does not contain enough elements for each of its loop variables in each iteration, empty values are used for the missing elements. The break and continue statements may be invoked inside body, with the same effect as in the for command. Foreach returns an empty string. EXAMPLES
This loop prints every value in a list together with the square and cube of the value: set values {1 3 5 7 2 4 6 8} ;# Odd numbers first, for fun! puts "Value Square Cube" ;# Neat-looking header foreach x $values { ;# Now loop and print... puts " $x [expr {$x**2}] [expr {$x**3}]" } The following loop uses i and j as loop variables to iterate over pairs of elements of a single list. set x {} foreach {i j} {a b c d e f} { lappend x $j $i } # The value of x is "b a d c f e" # There are 3 iterations of the loop. The next loop uses i and j to iterate over two lists in parallel. set x {} foreach i {a b c} j {d e f g} { lappend x $i $j } # The value of x is "a d b e c f {} g" # There are 4 iterations of the loop. The two forms are combined in the following example. set x {} foreach i {a b c} {j k} {d e f g} { lappend x $i $j $k } # The value of x is "a d e b f g c {} {}" # There are 3 iterations of the loop. SEE ALSO
for(n), while(n), break(n), continue(n) KEYWORDS
foreach, iteration, list, looping Tcl foreach(n)

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