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Full Discussion: tcsh - understanding difference between "echo string" and "echo string > /dev/stdout"
Top Forums Shell Programming and Scripting tcsh - understanding difference between "echo string" and "echo string > /dev/stdout" Post 302668597 by marcink on Monday 9th of July 2012 03:01:53 PM
Old 07-09-2012
Quote:
Originally Posted by shamrock
The first line "Redirected to STDOUT" which you expect to show up in the file mystdout got overwritten by the last one "Should default to STDOUT without redirection"...and this will happen with any sh not just the tcsh...and by appending to mystdout you will see both the lines there...
Code:
./out_to_streams.csh >> mystdout

Tried it and I get the same result. I've tried "append redirect" (i.e. ">>") on the command line as suggested, and it did not work. I changed it in the script as well:
Code:
#!/bin/tcsh -f

echo Redirected to STDOUT >> /dev/stdout
echo Redirected to STDERR >> /dev/stderr

echo Should default to STDOUT without redirection

And "Redirect to STDOUT" still gets lost. I've tried all four combinations (i.e. ">" vs ">>" in script and on command line), and in all cases "Redirect to STDOUT" gets lost.

Is there some bizarre handling of the IO streams and redirects in tcsh that can explain this behavior?
 

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LEARN ABOUT CENTOS

systemd-cat

SYSTEMD-CAT(1)							    systemd-cat 						    SYSTEMD-CAT(1)

NAME

       systemd-cat - Connect a pipeline or program's output with the journal

SYNOPSIS

       systemd-cat [OPTIONS...] [COMMAND] [ARGUMENTS...]

       systemd-cat [OPTIONS...]

DESCRIPTION

       systemd-cat may be used to connect STDOUT and STDERR of a process with the journal, or as a filter tool in a shell pipeline to pass the
       output the previous pipeline element generates to the journal.

       If no parameter is passed, systemd-cat will write everything it reads from standard input (STDIN) to the journal.

       If parameters are passed, they are executed as command line with standard output (STDOUT) and standard error output (STDERR) connected to
       the journal, so that all it writes is stored in the journal.

OPTIONS

       The following options are understood:

       -h, --help
	   Prints a short help text and exits.

       --version
	   Prints a short version string and exits.

       -t, --identifier=
	   Specify a short string that is used to identify the logging tool. If not specified, no identification string is written to the journal.

       -p, --priority=
	   Specify the default priority level for the logged messages. Pass one of "emerg", "alert", "crit", "err", "warning", "notice", "info",
	   "debug", or a value between 0 and 7 (corresponding to the same named levels). These priority values are the same as defined by
	   syslog(3). Defaults to "info". Note that this simply controls the default, individual lines may be logged with different levels if they
	   are prefixed accordingly. For details see --level-prefix= below.

       --level-prefix=
	   Controls whether lines read are parsed for syslog priority level prefixes. If enabled (the default), a line prefixed with a priority
	   prefix such as "<5>" is logged at priority 5 ("notice"), and similar for the other priority levels. Takes a boolean argument.

EXIT STATUS

       On success, 0 is returned, a non-zero failure code otherwise.

EXAMPLES

       Example 1. Invoke a program

       This calls /bin/ls with STDOUT/STDERR connected to the journal:

	   # systemd-cat ls

       Example 2. Usage in a shell pipeline

       This builds a shell pipeline also invoking /bin/ls and writes the output it generates to the journal:

	   # ls | systemd-cat

       Even though the two examples have very similar effects the first is preferable since only one process is running at a time, and both STDOUT
       and STDERR are captured while in the second example only STDOUT is captured.

SEE ALSO

       systemd(1), systemctl(1), logger(1)

systemd 208															    SYSTEMD-CAT(1)
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