Tip: traversing arrays in C-Shell

Below I have described two methods to traverse arrays in C-Shell - one uses the foreach loop and other while loop.
In both cases, the important thing to note is that array index in C-shell starts with '1' instead of '0' as in most programming languages, like C, C++, Java, Perl.


set a = (1 2 3 4)
set b = (5 6 7 8)
 
Method 1 - using the foreach loop, iterating on one array as the foreach index, and the accessing the other array inside the loop body using the index operator "[]"
set i = 1
foreach x ( `echo $a` )
  echo "x = $x b = $b[$i]"
  @ i = $i + 1
end
 
Output: 
x = 1 b = 5
x = 2 b = 6
x = 3 b = 7
x = 4 b = 8

Method 2 - using the while loop. Iterating on the size of array and accessing both the arrays inside the loop body using the index operator "[]"

set i = 1
while ($i <= 4)
  echo "a = $a[$i] b = $b[$i]"
  @ i = $i + 1
end
 
Output:
a = 1 b = 5
a = 2 b = 6
a = 3 b = 7
a = 4 b = 8

gdb stops at SIGPIPE

By default, gdb captures SIGPIPE of a process and pauses it. However, some program ignores SIGPIPE. So, the default behavour of gdb is not desired when debugging those program. To avoid gdb stopping in SIGPIPE, use the folloing command in gdb:

handle SIGPIPE nostop noprint pass