Sponsored Content
Full Discussion: Unix Shell Scripting
Top Forums UNIX for Dummies Questions & Answers Unix Shell Scripting Post 302686489 by Don Cragun on Tuesday 14th of August 2012 04:57:21 PM
Old 08-14-2012
First, there are two flavors of the echo utility. The BSD-based version of echo concatenates all of the operands it is given and write them to standard output followed by a <newline>. If the -n option is present it doesn't output the <newline>. I assume this is the version of echo you have on your system. (On the UNIX System V-based version of echo -n is not an option; it is just another operand to be printed. But there are several escape sequences in the string operands that the System V echo will translate ("\t" -> <tab>, "\n" -> <newline>, "\0" -> skip the remainder of this and any following operand and skip the normal trailing <newline>, etc.) that the BSD echo will not change.) If you want to output some text without the normal trailing <newline> in a way that will be portable to all UNIX and Linux systems, use the printf utility instead of echo.

So, your cout << "string" being roughly equivalent to [icode]echo -n "string" is pretty close. But echo $1 is also an output statement; not an input statement. I'm more of a C guy, than C++. In C it is roughly equivalent to printf("%s\n", argv[1]);. The equivalence is would be exact if you used "$1" instead of $1 because if the string isn't quoted and you have the default setting for $IFS, any sequences of one or more <space> and <tab> characters will be translated to a single space and passed to the echo command as individual operands instead of as a single string.

In the shells (bash, ksh, sh, ...), $n (1 <= n <= 9) refers to the 9th argument given to to the shell script when it was invoked. If you use ${n}, n can be greater than 9. $0 refers to the name of the script (like argv[0] in a C or C++ program). So, if you have a regular file with the execute bit set named "script" that contains something like:
Code:
#!/bin/ksh
echo -n "There once was a "
echo $1
echo -n "that "
echo $2
echo -n "who liked to " 
echo $3
echo -n "There once was a " $1 " that " $2 " who liked to " $3

and invoked it as:
Code:
script man "spent a lot of time in a swimming pool" "win gold medals!"

the output should be something like:
Code:
There once was a man
 that spent a lot of time in a swimming pool
 who liked to win gold medals!
There once was a man that spent a lot of time in a swimming pool who liked to win gold medals!

 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

Unix shell scripting

I need to write a script which analyses an invoice file, counting the amount of pages in the file to be printed per account number and per invoice. The account numbers are stored in another file which has instructions on what do with ach customers invoice as per their account number. please... (6 Replies)
Discussion started by: la_burton
6 Replies

2. Shell Programming and Scripting

difference between AIX shell scripting and Unix shell scripting.

please give the difference between AIX shell scripting and Unix shell scripting. (2 Replies)
Discussion started by: haroonec
2 Replies

3. Shell Programming and Scripting

Unix shell scripting

Hi, we are writing this fields dynamically retrieved from database and writing into the file. $bmpRec = $bmpRec.'|'.$cust_id; # sp4 $bmpRec = $bmpRec.'|'.$serv_id; # sp5 $bmpRec = $bmpRec.'|'.$site_id; # sp6 $bmpRec = $bmpRec.'|'.$loc_id; # sp7 ... (4 Replies)
Discussion started by: Maruthi Kunnuru
4 Replies

4. Shell Programming and Scripting

Unix Shell Scripting

Hi All, Greetings!! I am trying to write a script that will get me the syslog.log file output of last week... That is ...my cron will run on Monday and will get me the syslog output of previous week , last monday-last sunday. I tried using date formatting and tail..but did not succeed.... (4 Replies)
Discussion started by: premamadhuri
4 Replies

5. UNIX for Advanced & Expert Users

Need your Help on Unix Shell Scripting.........

Hi Friends, 1. Bash Shell Scrpt to take backup at evening 2. I need a bash shell script for killing all processes. (5 Replies)
Discussion started by: vinayraj
5 Replies

6. Shell Programming and Scripting

Unix Shell Scripting

I 'm new to unix shell scripting can some one guide me to any e-book or link from where i can learn unix shell scripting .. i want to learn create interactive scripts for my day to day solaris work. Any help would be appreciated (1 Reply)
Discussion started by: fugitive
1 Replies

7. UNIX for Dummies Questions & Answers

Unix Shell Scripting( Calling from Unix to PLSQL)

Hello Experts, I have the following questions to be discussed here at this esteemed discussion forum. I have two Excel sheets which contain Unix Commands llike creating directory the structure/ftp/Copy/Zip etc to basically create an environment. I need help in understanding some of... (1 Reply)
Discussion started by: faizsaadq
1 Replies

8. Shell Programming and Scripting

UNIX shell scripting

I am new to Unix.. Can someone please help me to understand the concept of Login shell and non login shell ? what exactly the difference between them :confused: (1 Reply)
Discussion started by: lokita jain
1 Replies

9. Programming

unix Shell scripting

Hi All, need help to complete the automation but stuck at a perticular situation below is the code <code> fixed_function_name { code.... code.... variable_map= { a="/a" b="/b" c="/c" so on... } (7 Replies)
Discussion started by: yadavricky
7 Replies

10. UNIX for Beginners Questions & Answers

UNIX Shell Scripting

Describe in short the word completion feature of the tcsh Completion works anywhere in the command line, not at just the end, for both commands and filenames. Type part of a word and hit the Tab key, and the shell replaces the incomplete word with the complete one in the input buffer. The... (1 Reply)
Discussion started by: Elena Lauren
1 Replies
print(1)							   User Commands							  print(1)

NAME
print - shell built-in function to output characters to the screen or window SYNOPSIS
ksh print [-Rnprsu [n]] [arg]... ksh93 print [-Renprs] [-f format] [-u fd] [string...] DESCRIPTION
ksh The shell output mechanism. When no options are specified, or when an option followed by ' a - is specified, or when just - is specified, the arguments are printed on standard output as described by echo(1). ksh93 By default, print writes each string operand to standard output and appends a NEWLINE character. Unless, the -r, -R, or -f option is speciifed, each character in each string operand is processed specially as follows: a Alert character.  Backspace character. c Terminate output without appending NEWLINE. The remaining string operands are ignored. E Escape character (ASCII octal 033). f FORM FEED character. NEWLINE character. Tab character. v Vertical tab character. \ Backslash character. x The 8-bit character whose ASCII code is the 1-, 2-, or 3-digit octal number x. OPTIONS
ksh The following options are supported by ksh: -n Suppresses new-line from being added to the output. -r-R Raw mode. Ignore the escape conventions of echo. The -R option prints all subsequent arguments and options other than -n. -p Cause the arguments to be written onto the pipe of the process spawned with |& instead of standard output. -s Cause the arguments to be written onto the history file instead of standard output. -u [ n ] Specify a one digit file descriptor unit number n on which the output is placed. The default is 1. ksh93 The following options are supported by ksh93: -e Unless -f is specified, process sequences in each string operand as described above. This is the default behavior. If both -e and -r are specified, the last one specified is the one that is used. -f format Write the string arguments using the format string format and do not append a NEWLINE. See printf(1) for details on how to specify format. When the -f option is specified and there are more string operands than format specifiers, the format string is reprocessed from the beginning. If there are fewer string operands than format specifiers, then outputting ends at the first unneeded for- mat specifier. -n Do not append a NEWLINE character to the output. -p Write to the current co-process instead of standard output. -r Do not process sequences in each string operand as described above. -R If both -e and -r are specified, the last one specified is the one that is used. -s Write the output as an entry in the shell history file instead of standard output. -u fd Write to file descriptor number fd instead of standard output. The default value is 1. EXIT STATUS
The following exit values are returned: 0 Successful completion. >0 Output file is not open for writing. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Availability |SUNWcsu | +-----------------------------+-----------------------------+ SEE ALSO
echo(1), ksh(1), ksh93(1), printf(1), attributes(5) SunOS 5.11 27 Mar 2008 print(1)
All times are GMT -4. The time now is 02:18 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy