Visit Our UNIX and Linux User Community

Use parameter expansion over a parameter expansion in bash.

Thread Tools Search this Thread
Top Forums Shell Programming and Scripting Use parameter expansion over a parameter expansion in bash.
# 8  
Old 01-28-2020
It's interesting that on "zsh" it works
Use parameter expansion over a parameter expansion in bash.-zshpng
These 2 Users Gave Thanks to nezabudka For This Post:
# 9  
Old 01-28-2020
Really interesting. By definition it is a variable modifier that means the LHS must be a variable. Nesting can only be attempted on the RHS that is a string.
Apparently in zsh the LHS can be a string that means it is a full functional operator.
This User Gave Thanks to MadeInGermany For This Post:

Previous Thread | Next Thread
Test Your Knowledge in Computers #684
Difficulty: Medium
According to both NetMarketShare and WikiMedia, Safari claimed a mobile market share of over 40% in 2019.
True or False?

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Bash : Parameter expansion ${var:-file*}

Example data $ ls *somehost* #!/bin/bash #FILES="*.log" FILES=${FILES:-*.log} for x in $FILES do ip="${x%%_*}" # isolate IP address x="${x##*_}" # isolate hostname hnam="${x%.*}" # Remove the ".log"... (2 Replies)
Discussion started by: popeye
2 Replies

2. Shell Programming and Scripting

Bash : More parameter expansion and IFS

I am trying to become more fluent with the interworking of bash and minimize the number of external calls. Sample Data. This will be the response of the snmp query. SNMPv2-MIB::sysName.0 = STRING: SomeHostName SNMPv2-MIB::sysObjectID.0 = OID: SNMPv2-SMI::enterprises.9.1.1745... (5 Replies)
Discussion started by: sumguy
5 Replies

3. Shell Programming and Scripting

Bash Parameter Expansion

#!/bin/bash SNMPW='/usr/bin/snmpwalk' while read h i do loc=$($SNMPW -v3 -u 'Myusername' -l authPriv -a SHA -A 'Password1' -x AES -X 'Password2' $i sysLocation.0 2>/dev/null) loc=${loc:-" is not snmpable."} loc=${loc##*: } loc=${loc//,/} echo "$i,$h,$loc" done < $1 My question is ... ... (1 Reply)
Discussion started by: sumguy
1 Replies

4. Shell Programming and Scripting

Bash Parameter Expansion

I have made the following examples that print various parameter expansions text: iv-hhz-sac/hpac/hhz.d/iv.hpac..hhz.d.2016.250.070018.sac (text%.*): iv-hhz-sac/hpac/hhz.d/iv.hpac..hhz.d.2016.250.070018 (text%%.*): iv-hhz-sac/hpac/hhz (text#*.): d/iv.hpac..hhz.d.2016.250.070018.sac... (2 Replies)
Discussion started by: kristinu
2 Replies

5. UNIX for Dummies Questions & Answers

Parameter Expansion with regular expression

Hello experts, I am exploring parameter expansion, and trying to cut the fields in a URL. Following is the requirement: I have // abc.nnt /dir1/dir2/dir3/dir4/ What i need to get is the path after dir3, and dir3 will be passed. output that i need is... (1 Reply)
Discussion started by: gjarms
1 Replies

6. Shell Programming and Scripting

Parameter expansion not working for all strings...

I'm trying to write a script that parses my music collection and hard link some filenames that my media player doesn't like to other names. To do this I need to extract the name and remove alla non ASCII characters from that and do a cp -l with the result. Problem is this: 22:16:58 $... (8 Replies)
Discussion started by: refuser
8 Replies

7. Shell Programming and Scripting

Bash parameter expansion from a config file

Hi - I am trying to do a simple config file with known variable names in it, e.g.: contents of config file a.conf: -a -b $work -c $host simplified contents of bash script file: work='trunk' host='alaska' opts=$(tr '\n' ' ' < a.conf) opts="$opts $*" mycommand $opts arg1 arg2 The... (3 Replies)
Discussion started by: mrengert
3 Replies

8. Shell Programming and Scripting

Need help with parameter expansion

Say you have this numeric variable that can be set by the user but you never want it to leave a certain range when it gets printed. How could you use parameter expansion such that it will never expand outside of that boundary? Thanks ---------- Post updated at 11:09 PM ---------- Previous update... (3 Replies)
Discussion started by: stevenswj
3 Replies

9. Shell Programming and Scripting

Need to print the expansion of the found string (the expansion is beween two delimiters '-' , '||'

Hi , could anyone help me out with this problem. sample.txt has this content : u001- this is used for project1 || u002- this is used for p2|| not to be printed u003- this is used for project3 || u004- this is used for p4 || u005- this is used for project5 || u006- this is used for p6... (9 Replies)
Discussion started by: Balaji PK
9 Replies

10. Shell Programming and Scripting

removing html tags via parameter expansion

Hi all- I have a variable that contains a web page: echo $STUFF <html> <head> <title>my page</title></head> <body> blah blah etc.. Can I use the shell's parameter expansion abilities to remove just the tags? I thought that FIXHTML=${STUFF//<*>/} might do it, but it didn't seem to... (2 Replies)
Discussion started by: rev66
2 Replies

Featured Tech Videos