I have some difficulties with the sed command on Unix AIX IBM). It's seems also on linux...
here is a line of my file, that i would change :
# id=<$IdEDFRGB.RR '" fgg t uj67575 uj:$ g re ee >
it should be after the subsitution :
# id=<$Id22 02 21 17:13$ g re ee >f rgrge
when i use this sed command (after initialize the DT variable) :
sed "s/<\$Id.*\$/<\$Id${DT}\$/g"
I obtain :
# id=<$Id22 02 2021 17:41$
I loose the right part. Someone could help me ?
thx
You need to escape the backslashes in the regexp so they're treated as literal backslash by the shell's string parser, and then they will escape the $ in the regexp. You also need to escape the $ in the regexp so that they don't start a variable expansion.
sed "s/<\\\$Id.*\\\$/<\$Id${DT}\$/g"
If you use echo ".*\$", you will see .*$, the pattern matches any text up to the string end, that's why your "right side" is eaten up. $ in a double quoted string is used to expand variables and in order to use a literal $, you need to use a "\$" char combination. In order to introduce a \$ literal text into a double quoted string, you need "\\$".
Use single quotes to avoid these issues, only use double quotes around the variable:
sed 's/\(<\$Id\).*\(\$\)/\1'"$DT"'\2/' file
Here, \(<\$Id\) is a capturing group 1 (\1) that captures <$Id literal text and \(\$\) is a capturing group 2 (\2) that captures a $ char. The $DT is within double quotes and is expanded correctly.
Using capturing groups, you avoid having to double the literal text both inside the pattern and the replacement.