Re: [CentOS] shell script strangeness...
Craig White wrote: That works fine one CentOS 5 (double quotes and backtics) but not on CentOS 4.6 Thanks...I guess it's good enough for now. Craig ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos I can only imagine it is working in 4.6 because the result of grep entry_chooser.js /var/log/httpd/access_log is either empty or 1 word. The test syntax [ -z xxx ] would report the too many arguments error whenever the grep returned more than one word. You can test this at your command line by typing in:- [ -z one ] and [ -z one two three four five ] The first will return false but you'll just see another bash prompt, the second will report the too many arguments error. This is certainly the case for me using RHEL4.6, so I would imagine CentOS4.6 should be the same. You can also see it explained by these commands and results:- [EMAIL PROTECTED] ~]$ [ -z ] [EMAIL PROTECTED] ~]$ echo $? 0 [EMAIL PROTECTED] ~]$ [ -z one ] [EMAIL PROTECTED] ~]$ echo $? 1 [EMAIL PROTECTED] ~]$[ -z one two three four ] -bash: [: too many arguments [EMAIL PROTECTED] ~]$ echo $? 2 [EMAIL PROTECTED] ~]$ I hope this helps you understand why it is working on one machine but not another. Ian PS: I always prefer $(cmd) to backtics for readability. e.g. if [ -z $(grep entry_chooser.js /var/log/httpd/access_log) ] PPS: grep -q works for me on RHEL4.6 and CentOS5.1 ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] shell script strangeness...
On Fri, 2008-05-16 at 17:03 +0930, Ian Blackwell wrote: Craig White wrote: That works fine one CentOS 5 (double quotes and backtics) but not on CentOS 4.6 Thanks...I guess it's good enough for now. Craig ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos I can only imagine it is working in 4.6 because the result of grep entry_chooser.js /var/log/httpd/access_log is either empty or 1 word. The test syntax [ -z xxx ] would report the too many arguments error whenever the grep returned more than one word. You can test this at your command line by typing in:- [ -z one ] and [ -z one two three four five ] The first will return false but you'll just see another bash prompt, the second will report the too many arguments error. This is certainly the case for me using RHEL4.6, so I would imagine CentOS4.6 should be the same. You can also see it explained by these commands and results:- [EMAIL PROTECTED] ~]$ [ -z ] [EMAIL PROTECTED] ~]$ echo $? 0 [EMAIL PROTECTED] ~]$ [ -z one ] [EMAIL PROTECTED] ~]$ echo $? 1 [EMAIL PROTECTED] ~]$[ -z one two three four ] -bash: [: too many arguments [EMAIL PROTECTED] ~]$ echo $? 2 [EMAIL PROTECTED] ~]$ I hope this helps you understand why it is working on one machine but not another. Ian PS: I always prefer $(cmd) to backtics for readability. e.g. if [ -z $(grep entry_chooser.js /var/log/httpd/access_log) ] PPS: grep -q works for me on RHEL4.6 and CentOS5.1 makes a lot of sense - thanks Craig ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
[CentOS] shell script strangeness...
On my CentOS 4.6 server, this works... if [ -z `grep entry_chooser.js /var/log/httpd/access_log` ] On my CentOS 5.1 server, this gives me the following error... ./test_file.scr: line 3: [: too many arguments Can anyone explain why the difference and suggest something that makes both cases happy? Thanks Craig ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] shell script strangeness...
Craig White wrote: On my CentOS 4.6 server, this works... if [ -z `grep entry_chooser.js /var/log/httpd/access_log` ] On my CentOS 5.1 server, this gives me the following error... ./test_file.scr: line 3: [: too many arguments Can anyone explain why the difference and suggest something that makes both cases happy? Thanks Craig ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos Not sure why 4.6 is allowing it, but your if test will be resolving to something like this:- if [ -z this line from your log file and another line and even more lines until your if test fails with too many arguments I hope you don't want me to keep typing to make the point ] To fix it, wrap the grep instead double quotes as well as the ticks - e.g. if [ -z `grep entry_chooser.js /var/log/httpd/access_log` ] Then the output from the grep will be seen as one long string, not a multitude of words from your log file. Ian smime.p7s Description: S/MIME Cryptographic Signature ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] shell script strangeness...
On Fri, May 16, 2008 at 02:07:10PM +0930, Ian Blackwell alleged: Craig White wrote: On my CentOS 4.6 server, this works... if [ -z `grep entry_chooser.js /var/log/httpd/access_log` ] On my CentOS 5.1 server, this gives me the following error... ./test_file.scr: line 3: [: too many arguments Can anyone explain why the difference and suggest something that makes both cases happy? Thanks Craig ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos Not sure why 4.6 is allowing it, but your if test will be resolving to something like this:- if [ -z this line from your log file and another line and even more lines until your if test fails with too many arguments I hope you don't want me to keep typing to make the point ] To fix it, wrap the grep instead double quotes as well as the ticks - e.g. if [ -z `grep entry_chooser.js /var/log/httpd/access_log` ] Then the output from the grep will be seen as one long string, not a multitude of words from your log file. Even better is to use 'grep -q' to avoid possibly large string expansions... if grep -q entry_chooser.js /var/log/httpd/access_log ;then -- Garrick Staples, GNU/Linux HPCC SysAdmin University of Southern California Please avoid sending me Word or PowerPoint attachments. See http://www.gnu.org/philosophy/no-word-attachments.html pgpF8kEh4F3yE.pgp Description: PGP signature ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] shell script strangeness...
On Fri, 2008-05-16 at 14:07 +0930, Ian Blackwell wrote: Craig White wrote: On my CentOS 4.6 server, this works... if [ -z `grep entry_chooser.js /var/log/httpd/access_log` ] On my CentOS 5.1 server, this gives me the following error... ./test_file.scr: line 3: [: too many arguments Can anyone explain why the difference and suggest something that makes both cases happy? Not sure why 4.6 is allowing it, but your if test will be resolving to something like this:- if [ -z this line from your log file and another line and even more lines until your if test fails with too many arguments I hope you don't want me to keep typing to make the point ] To fix it, wrap the grep instead double quotes as well as the ticks - e.g. if [ -z `grep entry_chooser.js /var/log/httpd/access_log` ] Then the output from the grep will be seen as one long string, not a multitude of words from your log file. That works fine one CentOS 5 (double quotes and backtics) but not on CentOS 4.6 Thanks...I guess it's good enough for now. Craig ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] shell script strangeness...
On Thu, 2008-05-15 at 22:00 -0700, Garrick Staples wrote: On Fri, May 16, 2008 at 02:07:10PM +0930, Ian Blackwell alleged: Craig White wrote: On my CentOS 4.6 server, this works... if [ -z `grep entry_chooser.js /var/log/httpd/access_log` ] On my CentOS 5.1 server, this gives me the following error... ./test_file.scr: line 3: [: too many arguments Can anyone explain why the difference and suggest something that makes both cases happy? Not sure why 4.6 is allowing it, but your if test will be resolving to something like this:- if [ -z this line from your log file and another line and even more lines until your if test fails with too many arguments I hope you don't want me to keep typing to make the point ] To fix it, wrap the grep instead double quotes as well as the ticks - e.g. if [ -z `grep entry_chooser.js /var/log/httpd/access_log` ] Then the output from the grep will be seen as one long string, not a multitude of words from your log file. Even better is to use 'grep -q' to avoid possibly large string expansions... if grep -q entry_chooser.js /var/log/httpd/access_log ;then for this purpose, -q didn't seem to matter much - thanks Craig ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
