Differences

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--- linux:pipe [2018/03/20 15:49] – [Pipe to a file] tmade
+++ linux:pipe [2022/02/16 04:34] (current) – [Pipe to a programm] tmade
@@ Line 7: / Line 7: @@
 ==== Pipe to a file ====
-  (stdin)  0     #Standart input
+  (stdin)  0     #Standard input
-  (stdout) 1     #Standart output
+  (stdout) 1     #Standard output
-  (stderr) 2     #Standart error output
+  (stderr) 2     #Standard error output
-  >              #redirects standart input
+  >              #redirects standard input
->             #redirects standart output
+>             #redirects standard output
->             #redirects standart error output
+>             #redirects standard error output
 Examples:
-  ls /opt/ /otherfile > list 2>&1          #Redirect standart output and standart error output to a file
+  ls /opt/ /otherfile > file 2>&1          #Redirect standard error output and standard output and to "file"
-  echo "This is a test" 1> /dev/null       #Redirects standart output to /dev/null
+  sudo -lU ${USER} > /dev/null 2>&1        #Redirect standard error output and standard output and to "/dev/null"
+  ls /opt /otherfile 2> /dev/null          #Redirect standard error output to /dev/null
+  programm &> file                         #Redirect stdout AND stderr to "file"
+  echo "This is a test" 1> /dev/null       #Redirects standard output to /dev/null
   ls xyz > info.txt 2> error.txt           #Output of ls will be redirected to "info.txt" (stdout) and if there is an error output (stderr) to "error.txt"
   ls /opt /otherfolder 2> /dev/null        #Output Standartoutput - standarterroroutput will be piped to /dev/null
-> /opt/file                             #Redirects standart error output
+> /opt/file                             #Redirects standard error output
->>  /opt/file                           #Redirects standart error output (appends)
+>>  /opt/file                           #Redirects standard error output (appends)
 **Explication check:**
   man -Len -Pless\ +/^REDIRECTION bash
 ==== Execution Dependency ====
   command1 && command2                     #Command2 is only executed if command1 completed without errors
   command1 || command2                     #Command2 is only executed if command1 completed with an error
+  command1 && command2 || command3         #
 ==== Error-handling ====
 To check if a process is running/ return code:
-SERVICE_NAME=apache2
+  SERVICE_NAME=apache2
   (ps -ef | grep $SERVICE_NAME  | grep -v grep && echo "$SERVICE_NAME is running") || echo "$SERVICE_NAME is not running"
   ps -ef | grep $SERVICE_NAME | grep -v grep && RESULT=running || RESULT=error
@@ Line 50: / Line 53: @@
 </code>
   innobackupex --apply-log $TARGET_FOLDER && /bin/echo "`/bin/date +'%d-%m-%Y %H:%M:%S'`: Backup successful." >> $BACKUPLOG || /bin/echo "`/bin/date +'%d-%m-%Y %H:%M:%S'`: Backup failed." >> $ERRLOGFILE
-  cp -a $(ls /var/log/nginx/*access.log.* | grep -E 'access\.log\.[1-3](\.gz)?$') /mnt/serverlogs/lb-web/
 ==== Pipe to a programm ====
-Output one command as input to another command:
+Output a command as input to another command:
   cat /etc/passwd | cut -d: -f1