csh

Redirect stderr to stdout in C shell

由 喜夏-厌秋 提交于 2019-11-26 15:29:54
问题 When I run the following command in csh , I got nothing, but it works in bash . Is there any equivalent in csh which can redirect the standard error to standard out? somecommand 2>&1 回答1: The csh shell has never been known for its extensive ability to manipulate file handles in the redirection process. You can redirect both standard output and error to a file with: xxx >& filename but that's not quite what you were after, redirecting standard error to the current standard output. However, if

How to determine the current shell I'm working on?

由 允我心安 提交于 2019-11-26 11:27:28
How can I determine the current shell I am working on? Would the output of the ps command alone be sufficient? How can this be done in different flavors of UNIX? DVK There are 3 approaches to finding the name of the current shell's executable: Please note that all 3 approaches can be fooled if the executable of the shell is /bin/sh but it's really a renamed bash , for example (which frequently happens). Thus your second question of whether ps output will do is answered with " not always ". echo $0 - will print the program name... which in the case of shell is the actual shell ps -ef | grep $$

Maximum length of command line argument that can be passed to SQL*Plus?

由 荒凉一梦 提交于 2019-11-26 08:59:57
问题 I am calling SQL*Plus from Linux C Shell: sqlplus username/password @file.sql var1 var2 var3 If I pass a string as var1 , how long can this string be? Is it governed by the OS? In this case: Linux version 2.6.9-100.ELsmp (mockbuild@x86-010.build.bos.redhat.com) (gcc version 3.4.6 20060404 (Red Hat 3.4.6-11)) #1 SMP Tue Feb 1 12:17:32 EST 2011 Update: Empirical testing yielded the following results: A command line argument of 5200 characters gave the error, \"Word too long.\" 1300 characters

Extract one word after a specific word on the same line

由 徘徊边缘 提交于 2019-11-26 07:48:04
问题 How can I extract a word that comes after a specific word in Linux (csh)? More precisely, I have a file which has a single line which looks like this: [some useless data] --pe_cnt 100 --rd_cnt 1000 [some more data] I want to extract the number 100 which is after the --pe_cnt word. I cannot use sed as that works only if you want to extract an entire line. Maybe I can use awk? Also, I have multiple files that have different values instead of 100 so I need something that extracts the value but

How to keep from duplicating path variable in csh

由 人走茶凉 提交于 2019-11-26 07:37:46
问题 It is typical to have something like this in your cshrc file for setting the path: set path = ( . $otherpath $path ) but, the path gets duplicated when you source your cshrc file multiple times, how do you prevent the duplication? EDIT: This is one unclean way of doing it: set localpaths = ( . $otherpaths ) echo ${path} | egrep -i \"$localpaths\" >& /dev/null if ($status != 0) then set path = ( . $otherpaths $path ) endif 回答1: you can use the following Perl script to prune paths of duplicates

How to determine the current shell I'm working on?

由 社会主义新天地 提交于 2019-11-26 03:31:47
问题 How can I determine the current shell I am working on? Would the output of the ps command alone be sufficient? How can this be done in different flavors of UNIX? 回答1: There are 3 approaches to finding the name of the current shell's executable: Please note that all 3 approaches can be fooled if the executable of the shell is /bin/sh but it's really a renamed bash , for example (which frequently happens). Thus your second question of whether ps output will do is answered with " not always ".

Can a shell script set environment variables of the calling shell? [duplicate]

由 时光怂恿深爱的人放手 提交于 2019-11-26 01:22:06
问题 This question already has answers here : Can I export a variable to the environment from a bash script without sourcing it? (7 answers) Closed 8 months ago . I\'m trying to write a shell script that, when run, will set some environment variables that will stay set in the caller\'s shell. setenv FOO foo in csh/tcsh, or export FOO=foo in sh/bash only set it during the script\'s execution. I already know that source myscript will run the commands of the script rather than launching a new shell,

Getting ssh to execute a command in the background on target machine

由 六眼飞鱼酱① 提交于 2019-11-26 01:03:10
问题 This is a follow-on question to the How do you use ssh in a shell script? question. If I want to execute a command on the remote machine that runs in the background on that machine, how do I get the ssh command to return? When I try to just include the ampersand (&) at the end of the command it just hangs. The exact form of the command looks like this: ssh user@target \"cd /some/directory; program-to-execute &\" Any ideas? One thing to note is that logins to the the target machine always

Getting ssh to execute a command in the background on target machine

由 南楼画角 提交于 2019-11-25 23:14:49
This is a follow-on question to the How do you use ssh in a shell script? question. If I want to execute a command on the remote machine that runs in the background on that machine, how do I get the ssh command to return? When I try to just include the ampersand (&) at the end of the command it just hangs. The exact form of the command looks like this: ssh user@target "cd /some/directory; program-to-execute &" Any ideas? One thing to note is that logins to the the target machine always produce a text banner and I have SSH keys set up so no password is required. I had this problem in a program
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