Use options like -A, -E, -T, -v to show control characters.
Yes - if the system uses GNU-cat (or some other non-standard-conforming variant). POSIX-cat has only one valid option: "-u" for unbuffered operation.
Three ways to avoid and/or manage "^M" characters:
First, DO NOT WRITE YOUR SCRIPTS IN WINDOWS AND THEN FTP THEM TO UNIX! This is how the overwhelming majority of misplaced ^M-characters come to pass.
Second, open the file in questsion in vi and then enter: ":set list". This will display non-printable characters: "^I" is a tab, "^M" is a (Windows-style) line feed, "$" is a newline character, etc.. use the command ":set nolist" to switch back to normal display.
Third, control your variable definitions:
will place a "^M" character between "foo" and "bar".
Hi friends, :)
In a shell script i found the following if condition.
echo -n "Which version of $1 do you want to restore ('0' to quit)? : "
read desired
if ${desired:=1} -ge $index ] ; then
echo "$0: Restore canceled by user: index value too big." >&2
exit 1
fi
Can... (1 Reply)
i have a paramter data_date in which i am passing a string value.i want to find out another paramter file_date from this.the logic is given below
if day of data_date = sunday or monday
then
file_date=data_date-1
else
file_date=data_date-2
i am passing data_date as 20061027.
how can i... (3 Replies)
Hi,
I am trying to execute this command, but is it not working, says "`;' unexpected"
eval $lgrep $SAM_CMD ; if ; then ; echo "No Error" ; fi
What i want is, return the command output, if it is non zero, say "No Error".
Thanks, John. (21 Replies)
Executed the following if conditions .. and got different results .
only (( )) gave correct o/p with all scenarios .
Can anybody please let me know what is the difference between and ] and ((condition)) when used with if condition.
And why each condition gave different result.
1.... (2 Replies)
hi,
I have some problems in my simple script about the redirect echo stdout command inside a condition. Why is the echo command inside the elif still execute in the else command
Here are my simple script
After check on the two diff output the echo stdout redirect is present in two diff... (3 Replies)
HI
My doubt may be basic one but I need to get it clarified..
When i use "if" condition that checks for many AND, OR logical conditions
like
if ]; then
return 0
fi
Even the if condition fails it returns as zero.. Any clue..
But if i add else condition like
if ]; ... (2 Replies)
Hi all
Unix newbie - please be gentle
Am modifying an existing script to error trap a variable with a length of 0
#!/bin/bash
ipfile='/var/data/bin/ipaddress'
] && ipold="$(< "$ipfile" )"
ipnew="$( wget -q -O - checkip.dyndns.org | sed -e 's/.*Current IP Address: //;s/<.*$//' )"
#... (6 Replies)
o/p of my command is given below
My requirement is
if Pnumber is 0 then
stabilization.Build.2013
else
stabilization.PBuild.2013.3 (11 Replies)
Discussion started by: nikhil jain
11 Replies
LEARN ABOUT OSX
cat
CAT(1) BSD General Commands Manual CAT(1)NAME
cat -- concatenate and print files
SYNOPSIS
cat [-benstuv] [file ...]
DESCRIPTION
The cat utility reads files sequentially, writing them to the standard output. The file operands are processed in command-line order. If
file is a single dash ('-') or absent, cat reads from the standard input. If file is a UNIX domain socket, cat connects to it and then reads
it until EOF. This complements the UNIX domain binding capability available in inetd(8).
The options are as follows:
-b Number the non-blank output lines, starting at 1.
-e Display non-printing characters (see the -v option), and display a dollar sign ('$') at the end of each line.
-n Number the output lines, starting at 1.
-s Squeeze multiple adjacent empty lines, causing the output to be single spaced.
-t Display non-printing characters (see the -v option), and display tab characters as '^I'.
-u Disable output buffering.
-v Display non-printing characters so they are visible. Control characters print as '^X' for control-X; the delete character (octal
0177) prints as '^?'. Non-ASCII characters (with the high bit set) are printed as 'M-' (for meta) followed by the character for the
low 7 bits.
EXIT STATUS
The cat utility exits 0 on success, and >0 if an error occurs.
EXAMPLES
The command:
cat file1
will print the contents of file1 to the standard output.
The command:
cat file1 file2 > file3
will sequentially print the contents of file1 and file2 to the file file3, truncating file3 if it already exists. See the manual page for
your shell (i.e., sh(1)) for more information on redirection.
The command:
cat file1 - file2 - file3
will print the contents of file1, print data it receives from the standard input until it receives an EOF ('^D') character, print the con-
tents of file2, read and output contents of the standard input again, then finally output the contents of file3. Note that if the standard
input referred to a file, the second dash on the command-line would have no effect, since the entire contents of the file would have already
been read and printed by cat when it encountered the first '-' operand.
SEE ALSO head(1), more(1), pr(1), sh(1), tail(1), vis(1), zcat(1), setbuf(3)
Rob Pike, "UNIX Style, or cat -v Considered Harmful", USENIX Summer Conference Proceedings, 1983.
STANDARDS
The cat utility is compliant with the IEEE Std 1003.2-1992 (``POSIX.2'') specification.
The flags [-benstv] are extensions to the specification.
HISTORY
A cat utility appeared in Version 1 AT&T UNIX. Dennis Ritchie designed and wrote the first man page. It appears to have been cat(1).
BUGS
Because of the shell language mechanism used to perform output redirection, the command ``cat file1 file2 > file1'' will cause the original
data in file1 to be destroyed!
The cat utility does not recognize multibyte characters when the -t or -v option is in effect.
BSD March 21, 2004 BSD