A built-in is simply a command that is part of the bash shell and not a separate program. For example the 'ls' command is a separate program that is executed as a child process. The export command is a built-in command that is part of bash and will not spawn a child process when invoked. Probably the simplest explanation is a built-in is a command that is part of the bash executable file while a "non built-in" command has a separate executable file. A good way to think of a function is a script within a script or a script within your interactive session. For example here is a function to check disk usage in your current directory:
If you were to type whats in code tags into your terminal and then type spacecheck, bash would run all the commands between the {}. If you were to include this in a script the commands in the {} would be executed whenever you use spacecheck as a command in the script. For example:
As you can see once a function is defined in either a script or interactive session it is used just like any other command.
Hi ,
I have three funcions f1, f2 and f3 .
f1 calls f2 and f2 calls f3 .
I have a global variable "period" which i want to pass to f3 .
Can i pass the variable directly in the definition of f3 ?
Pls help .
sars (4 Replies)
Hi.
Problem: I have to parse the payload of a packet. The payload could be in Big Endian Format (network byte order) or little. That depends on a flag present in the header of the packet.
Solution: A horrible solution could be to check for that flag everytime I have to read a field in the... (11 Replies)
This is my function which is creating three variables based on counter & writing these variable to database by calling another function writeRecord
but only one record is getting wrote in DB.... Please advise ASAP...:confused:
function InsertFtg
{
FTGSTR=""
echo "Saurabh is GREAT $#"
let... (2 Replies)
In gdb, I can call one function with command "call", but how can I step in the function? I don't want to restart the program, but the function had been executed, gdb will execute next statement, and I don't know how to recall the function. (4 Replies)
I have a script which does gunzip, zip and untar.
Input to the script is file name and file directory (where file is located)
I am reading the input parameters as follows:
FILENAME=$1
FILEDIR=$2
I have created 3 functions that are as follows:
1) gunzip file
2) unzip file... (2 Replies)
Hello All,
I would like to ask help from you on how to pass variable value from a function that has been called inside the function. I have created below and
put the variables in " ". Is there another way I can do this? Thank you in advance.
readtasklist() {
while read -r mod ver... (1 Reply)
Dear All.
I have a script, which process files one by one. In the script I have two functions.
one sftp files to different server
the other from existing file create file with different name.
My question is:
Will sftp function recognize files names , which are created in another... (1 Reply)
Hi,
I am having script which contains many functions. Need to print each function name at the starting of the function. Like below,
functionname()
{
echo "functionname"
commands....
}
I've tried like below,
func=`grep "()" scriptname | cut -d "(" -f1`
for i in $func
do
nawk -v... (4 Replies)
Hi All,
Good Day, seeking for your assistance on how to not perform my 2nd, 3rd,4th etc.. function if my 1st function is in else condition.
#Body
function1()
{
if
then
echo "exist"
else
echo "not exist"
}
#if not exist in function1 my all other function will not proceed.... (4 Replies)
Discussion started by: meister29
4 Replies
LEARN ABOUT OSX
script
SCRIPT(1) BSD General Commands Manual SCRIPT(1)NAME
script -- make typescript of terminal session
SYNOPSIS
script [-akq] [-t time] [file [command ...]]
DESCRIPTION
The script utility makes a typescript of everything printed on your terminal. It is useful for students who need a hardcopy record of an
interactive session as proof of an assignment, as the typescript file can be printed out later with lpr(1).
If the argument file is given, script saves all dialogue in file. If no file name is given, the typescript is saved in the file typescript.
If the argument command is given, script will run the specified command with an optional argument vector instead of an interactive shell.
The following options are available:
-a Append the output to file or typescript, retaining the prior contents.
-k Log keys sent to program as well as output.
-q Run in quiet mode, omit the start and stop status messages.
-t time
Specify time interval between flushing script output file. A value of 0 causes script to flush for every character I/O event. The
default interval is 30 seconds.
The script ends when the forked shell (or command) exits (a control-D to exit the Bourne shell (sh(1)), and exit, logout or control-D (if
ignoreeof is not set) for the C-shell, csh(1)).
Certain interactive commands, such as vi(1), create garbage in the typescript file. The script utility works best with commands that do not
manipulate the screen. The results are meant to emulate a hardcopy terminal, not an addressable one.
ENVIRONMENT
The following environment variable is utilized by script:
SHELL If the variable SHELL exists, the shell forked by script will be that shell. If SHELL is not set, the Bourne shell is assumed. (Most
shells set this variable automatically).
SEE ALSO csh(1) (for the history mechanism).
HISTORY
The script command appeared in 3.0BSD.
BUGS
The script utility places everything in the log file, including linefeeds and backspaces. This is not what the naive user expects.
It is not possible to specify a command without also naming the script file because of argument parsing compatibility issues.
When running in -k mode, echo cancelling is far from ideal. The slave terminal mode is checked for ECHO mode to check when to avoid manual
echo logging. This does not work when in a raw mode where the program being run is doing manual echo.
BSD January 22, 2004 BSD