Replacing the value of specific field in a table-like string stored as bash variable - bash

Question

I am looking for a way to replace (with 0) a specific value (1043252782) in a "table-like" string stored as a bash variable. The output of echo "$var"looks like this:
5 Reallocated_Sector_Ct 0x0033 100 100 010 Pre-fail Always - 0
7 Seek_Error_Rate 0x000f 090 060 045 Pre-fail Always - 1043252782
10 Spin_Retry_Count 0x0013 100 100 097 Pre-fail Always - 0
187 Reported_Uncorrect 0x0032 100 100 000 Old_age Always - 0
After the replacement echo "$var" should look like this:
5 Reallocated_Sector_Ct 0x0033 100 100 010 Pre-fail Always - 0
7 Seek_Error_Rate 0x000f 090 060 045 Pre-fail Always - 0
10 Spin_Retry_Count 0x0013 100 100 097 Pre-fail Always - 0
187 Reported_Uncorrect 0x0032 100 100 000 Old_age Always - 0
Is there a way to do this without saving the content of $var to a file and directly manipulating it within the bash (shell script)?
Maby with awk? I can select the value in the 10th field of the second record with awk and pattern matching ("7 Seek_Error_Rate ....") like this:
echo "$var" | awk '/^ 7/{print $10}'
Maby there is some way doing it with awk (or other cli-tool) to replace it and store it back into $var? Also, the value changes over time, but the structure remains the same (some record at the 10th field).

Answer 1

You can change a specific string directly in the shell:
var=${var/1043252782/0}
To replace final number of second line, you could use awk or sed:
var=$(awk 'NR==2 { sub(/[0-9]+$/,0) }1' <<<"$var")
var=$(sed '2s/[0-9][0-9]*$/0/' <<<"$var")
If you don't know which line it will be, you can match a known string:
var=$(awk '/Seek_Error_Rate/{ sub(/[0-9]+$/,0) }1' <<<"$var")
var=$(sed '/Seek_Error_Rate/s/[0-9][0-9]*$/0/' <<<"$var")

Answer 2

You can use a here-string to feed the variable as input to awk.
Use sub() to perform a regular expression replacement.
var=$(awk '{sub(/1043252782$/, "0")}1' <<<"$var")

Answer 3

Using sed
$ var=$(sed '/1043252782$/s//0/' <<< "$var")
$ echo "$var"
5 Reallocated_Sector_Ct 0x0033 100 100 010 Pre-fail Always - 0
7 Seek_Error_Rate 0x000f 090 060 045 Pre-fail Always - 0
10 Spin_Retry_Count 0x0013 100 100 097 Pre-fail Always - 0
187 Reported_Uncorrect 0x0032 100 100 000 Old_age Always - 0

Answer 4

if you don't wanna ruin formatting of tabs and spaces :
{m,g}wk NF=NF FS=' 1043252782$' OFS=' 0'
:
5 Reallocated_Sector_Ct 0x0033 100 100 010 Pre-fail Always - 0
7 Seek_Error_Rate 0x000f 090 060 045 Pre-fail Always - 0
10 Spin_Retry_Count 0x0013 100 100 097 Pre-fail Always - 0
187 Reported_Uncorrect 0x0032 100 100 000 Old_age Always - 0
or doing the whole file in one single shot :
awk NF=NF FS=' 1043252782\n' OFS=' 0\n' RS='^$' ORS=
awk NF=NF FS=' 1043252782\n' OFS=' 0\n' RS= -- (This might work too but I'm not too well versed in any side effects for blank RS)