CODEWITHSUNDEEP
sed
Mem6
Mem6

Reputation: 25

Sed - increment all values greater than x

I want to increment snapshots numbering of all snapshots starting from certain snapshot (by using sed). How to increment snapshot numbering starting for example from snapshot=22?

// I have already found the command which increment whole snapshot numbering sed -r 's/(snapshot=)([0-9]+)/echo \1$((\2+1))/ge' myInputFile

I have file which looks like that:

#-----------
snapshot=4
#-----------
time=1449929
mem_heap_B=110
mem_heap_extra_B=40
mem_stacks_B=0
heap_tree=peak
#-----------
snapshot=5
#-----------
time=1449929
mem_heap_B=110
mem_heap_extra_B=40
mem_stacks_B=0
heap_tree=peak
.
.
.
#-----------
snapshot=22
#-----------
time=1448920
mem_heap_B=10
mem_heap_extra_B=24
mem_stacks_B=0
heap_tree=detailed
.
.
.
#-----------
snapshot=46
#-----------
time=1449964
mem_heap_B=110
mem_heap_extra_B=24
mem_stacks_B=0
heap_tree=detailed
.
.
.
#-----------
snapshot=172
#-----------
time=1448920
mem_heap_B=10

I want to get following output:

#-----------
snapshot=4
#-----------
time=1449929
mem_heap_B=110
mem_heap_extra_B=40
mem_stacks_B=0
heap_tree=peak
#-----------
snapshot=5
#-----------
time=1449929
mem_heap_B=110
mem_heap_extra_B=40
mem_stacks_B=0
heap_tree=peak
.
.
.
#-----------
snapshot=23
#-----------
time=1448920
mem_heap_B=10
mem_heap_extra_B=24
mem_stacks_B=0
heap_tree=detailed
.
.
.
#-----------
snapshot=47
#-----------
time=1449964
mem_heap_B=110
mem_heap_extra_B=24
mem_stacks_B=0
heap_tree=detailed
.
.
.
#-----------
snapshot=173
#-----------
time=1448920
mem_heap_B=10

Upvotes: 0

Views: 40

Answers (1)

Wintermute
Wintermute

Reputation: 44063

You will find it difficult to do that with sed because sed doesn't have built-in arithmetic functionality (and implementing it in pure sed is not a sane idea).

However, it is quite simple with awk:

awk -F = 'BEGIN { OFS = FS } $1 == "snapshot" && $2 >= 22 { ++$2 } 1' filename

This works by splitting lines into fields at = separators, and then:

BEGIN {
  OFS = FS                      # use the same separator in the output
}                               # as for the input

$1 == "snapshot" && $2 >= 22 {  # if the first field in a line is "snapshot"
                                # and the second larger than or equal to 22:

  ++$2                          # increment the second field
}
1                               # print the resulting line (unchanged if the
                                # condition was not met)

Upvotes: 2

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