Expr command
From DD-WRT Wiki
(Difference between revisions)
| Revision as of 19:00, 9 January 2009 (edit) Alvin (Talk | contribs) m ← Previous diff |
Current revision (07:39, 30 September 2012) (edit) (undo) Harjan (Talk | contribs) |
||
| (3 intermediate revisions not shown.) | |||
| Line 1: | Line 1: | ||
| - | You are here: '''[[Main_Page|DD-WRT wiki mainpage]] / [[Telnet/SSH_and_the_Command_Line|SSH/Telnet & The CLI]] / expr ''' | + | You are here: '''[[Main_Page|DD-WRT wiki mainpage]] / [[Index:Scripting|Scripting]] / [[Telnet/SSH_and_the_Command_Line|SSH/Telnet & The CLI]] / expr ''' |
| '''expr''' is the expression command in bourne type shells. On the WRT, expr is handled by busybox. | '''expr''' is the expression command in bourne type shells. On the WRT, expr is handled by busybox. | ||
| Line 6: | Line 6: | ||
| - | ~ # '''expr 5 | + | ~ # '''expr 5 + 6''' |
| 11 | 11 | ||
| Line 26: | Line 26: | ||
| - | [[Category: | + | [[Category:Scripts]] |
| - | + | [[Category:Command-line reference]] | |
| - | [[Category: | + | |
Current revision
You are here: DD-WRT wiki mainpage / Scripting / SSH/Telnet & The CLI / expr
expr is the expression command in bourne type shells. On the WRT, expr is handled by busybox.
expr takes expressions. The most common expressions deal with simple arithmetic operations:
~ # expr 5 + 6 11
~ # expr 39 / 4 9
Loop counter example:
#!/bin/sh # while lc < 10 do lc=1 while [ $lc -lt 10 ] ; do lc=`expr $lc + 1` echo LoopCount: $lc done
Try expr --help for more details.