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Bash Script Capture Error Message


Not the intended behavior! its the bash manual. is that what you want. The code is this: #! /bin/bash echo "Submit Lab$1? \c" read choice if [ $choice = "y" ]; then echo "Sending to Prof's dropbox..." cp -r /path/to/lab$1 /path/to/dropbox else echo "Submission http://onlinetvsoftware.net/bash-script/bash-script-capture-error-code.php

I understand that I could use verbose mode, and that cp itself prints out errors, but as stated before, I'm doing this for the purpose of learning error catching in bash Try our newsletter Sign up for our newsletter and get our top new questions delivered to your inbox (see an example). A name for a well-informed person who is not believed? Verbs of buttons on websites spectral norm of block-wise sums of matrices Symbolic comparison of recursive functions Meaning of Guns and ghee Why are some programming languages Turing complete but lack

Bash Script Capture Output

Using parameter expansion, it is possible to perform a number of useful string manipulations. So what can you do about it? Export to PDF Export to Text 3 Responses to "Trap Errors, Exit Codes and Line Numbers within a Bash script (and some output redirection, too)" george youn Says: January If you read the Letters section in Linux Journal, you know I haven't covered this topic because, well, you have covered it for me!

Here's a quick example: #!/bin/sh mkdir / echo "return status is $?" mkdir /tmp/foobar echo "return status is $?" rmdir /tmp/foobar echo "return status is $?" rmdir /tmp echo "return status This will save more typing and promote laziness. # An error exit function function error_exit { echo "$1" 1>&2 exit 1 } # Using error_exit if cd $some_directory; then rm * Any ideas? Bash Script Error Command Not Found gdelmatto Says: January 17th, 2012 at 10:41 pm Well, i does nothing after all, because it's just wrong!

Here's a basic example function: makedirectory() { mkdir $1 status=$? Bash Script Capture Output From Command Verbatim copying and distribution of this entire article is permitted in any medium, provided this copyright notice is preserved. more stack exchange communities company blog Stack Exchange Inbox Reputation and Badges sign up log in tour help Tour Start here for a quick overview of the site Help Center Detailed However, the code you provided does not work for failed submissions.

Use set -u How often have you written a script that broke because a variable wasn't set? Bash Script Error Check Not the answer you're looking for? The first is some code, which does any particular action, for example assemble error information and send it by email, while the trap command itself specifies, under what condition it needs If you use find and xargs together, you should use -print0 to separate filenames with a null character rather than new lines.

Bash Script Capture Output From Command

And then try to find other places. Quote: ... Bash Script Capture Output Again, for readability you may want to use set -o errexit. Bash Script Regex Capture If you ask rm to delete a non-existent file, it will complain and your script will terminate. (You are using -e, right?) You can fix this by using -f, which will silently

david% touch "foo bar" david% find | xargs ls ls: ./foo: No such file or directory ls: bar: No such file or directory david% find -print0 | xargs -0 ls ./foo check over here But they all have in common, that it is hard to trap and trace unknown errors, especially if the script runs unattended. If you add a -p option then mkdir will create all the parent directories before creating the requested directory. Be atomic Sometimes you need to update a bunch of files in a directory at once, say you need to rewrite urls form one host to another on your website. Bash Script Catch Error

Ubuntu Ubuntu Insights Planet Ubuntu Activity Page Please read before SSO login Advanced Search Forum The Ubuntu Forum Community Ubuntu Specialised Support Development & Programming Programming Talk [SOLVED] Bash error message Is there a way to make a metal sword resistant to lava? Please note the script output we get this time: $ bash test.sh check if file exists: '/ksdjhfskdfkshd': ok. http://onlinetvsoftware.net/bash-script/bash-script-error-message.php I will look more into stderr redirects, as that seems to be where the "clean prompt" solution lies.

It is also important that your scripts return a meaningful exit status when they finish. Bash Script Error Log It does not print "Submission failed." when cp fails. These commands have been designed so that they WILL fail for the sake of documentary purposes. #!/bin/bash # trap handler: print location of last error and process it further # function

Now, why is this?

Convince people not to share their password with trusted others Using Map to convert Feet + Inches to Inches in a List of Lists Religious supervisor wants to thank god in This applies to compound commands if, while and until, and (unsurprisingly) { }. Line four gives us the "format" command not found, while line five is the message from the trap handler. Bash Script Error Exit A trap handler could look something like this: function my_trap_handler() { MYSELF="$0" # equals to my script name LASTLINE="$1" # argument 1: last line of error occurence LASTERR="$2" # argument 2: error

I know I have, many times. I added the line numbers in front on my own for better illustration. $ bash test.sh 1: rm: /ksdjhfskdfkshd: No such file or directory 2: test3.sh: line 22: exit status of Search Forums Show Threads Show Posts Tag Search Advanced Search Unanswered Threads Find All Thanked Posts Go to Page... learn unix and linux commands How to capture actual error http://onlinetvsoftware.net/bash-script/bash-script-catch-error-message.php Never (as in NEVER) try to delete something without checking for it's existence first!

It's good practice to make sure your exit code is 0 on success and non-zero otherwise, so that higher-level scripts can call your script and use its result code to handle It's not clear to me that this is an explicitly documented behaviour though. The Magical $?