In one of the Unix Programming FAQ's they have the following headers in the program to catch SIGCHLD
#include <sys/types.h> /* include this before any other sys headers */
#include <sys/wait.h> /* header for waitpid() and various macros */
#include <signal.h> /* header for signal... (5 Replies)
I have the following script:
(echo -n `curl http://www.example.com/scores.txt | grep mylocation`; date +%Y%m%d%H%M%S) >> myscores.txt
This script works fine, except that it places the timestamp at the end of the file myscores.txt. How do add the timestamp as the first column and then a tab and... (4 Replies)
Hi,
I'm trying to strip all lines between two headers in a file:
### BEGIN ###
Text to remove, contains all kinds of characters
...
Antispyware-Downloadserver.com (Germany)=http://www.antispyware-downloadserver.c
om/updates/
Antispyware-Downloadserver.com #2... (3 Replies)
Hi ,
I have a typical situation. I have 4 files and with different headers (number of headers is varible ).
I need to make such a merged file which will have headers combined from all files (comman coluns should appear once only).
For example -
File 1
H1|H2|H3|H4
11|12|13|14
21|22|23|23... (1 Reply)
Hi,
I found the following awk script to transpose multiple (3) columns to multiple rows:
#===
BEGIN {FS=","}
{
for (i=1;i<=NF;i++)
{
arr=$i;
if(nf<= NF)
nf=NF;
}
nr=NR
}
END {
for(i=1;i<=nf;i++)
{ (8 Replies)
Hi everyone,
Please some help over here. (I´m using cygwing)
I have files with 40 columns and 2000 lines in average. I´m trying to change the order position as follow.
Original columns position:... (3 Replies)
Hi friends,
I have data in tab separated file with headers like this :
*sml1 *sml3 *smln7 smfk9 smllf56...
Which shell command I should use if i want to extract entire columns that have header names beginning with "*" ? i want to copy these columns into another file.
Thanks, (14 Replies)
I am trying to reorder columns based on a value in a field in the attached file. Thank you :).
If $11 is not equal to "unknown", then in a new text file $4, $11, $7, $13
For example, row 24 $11 is not unknown
A_16_P39089234, chr10:76765556-76765615, KAT6B, 0.9337 (5 Replies)
Hi. Unix rookie here. Been looking for a few days for reference documents on how BSD UNIX lays the logical file format onto a disk. Goal is to view/edit with hex editor for data repair. Lots of docs are available for how to use Unix commands (like xxd), but I want to learn the map of how Unix... (4 Replies)
The below awk verifies the count and order of each text file in the directory. The script does execute and produce output, however the order of the headers are not compared to key. The portion in bold is supposed to do that. If the order of the headers in each text file is the same as key, then... (0 Replies)
Discussion started by: cmccabe
0 Replies
LEARN ABOUT REDHAT
begin
BEGIN(7) SQL Commands BEGIN(7)NAME
BEGIN - start a transaction block
SYNOPSIS
BEGIN [ WORK | TRANSACTION ]
INPUTS
WORK
TRANSACTION
Optional keywords. They have no effect.
OUTPUTS
BEGIN This signifies that a new transaction has been started.
WARNING: BEGIN: already a transaction in progress
This indicates that a transaction was already in progress. The current transaction is not affected.
DESCRIPTION
By default, PostgreSQL executes transactions in unchained mode (also known as ``autocommit'' in other database systems). In other words,
each user statement is executed in its own transaction and a commit is implicitly performed at the end of the statement (if execution was
successful, otherwise a rollback is done). BEGIN initiates a user transaction in chained mode, i.e., all user statements after BEGIN com-
mand will be executed in a single transaction until an explicit COMMIT [commit(7)] or ROLLBACK [rollback(7)]. Statements are executed more
quickly in chained mode, because transaction start/commit requires significant CPU and disk activity. Execution of multiple statements
inside a transaction is also useful to ensure consistency when changing several related tables: other clients will be unable to see the
intermediate states wherein not all the related updates have been done.
The default transaction isolation level in PostgreSQL is READ COMMITTED, wherein each query inside the transaction sees changes committed
before that query begins execution. So, you have to use SET TRANSACTION ISOLATION LEVEL SERIALIZABLE just after BEGIN if you need more rig-
orous transaction isolation. (Alternatively, you can change the default transaction isolation level; see the PostgreSQL Administrator's
Guide for details.) In SERIALIZABLE mode queries will see only changes committed before the entire transaction began (actually, before
execution of the first DML statement in the transaction).
Transactions have the standard ACID (atomic, consistent, isolatable, and durable) properties.
NOTES
START TRANSACTION [start_transaction(7)] has the same functionality as BEGIN.
Use COMMIT [commit(7)] or ROLLBACK [rollback(7)] to terminate a transaction.
Refer to LOCK [lock(7)] for further information about locking tables inside a transaction.
If you turn autocommit mode off, then BEGIN is not required: any SQL command automatically starts a transaction.
USAGE
To begin a user transaction:
BEGIN WORK;
COMPATIBILITY
SQL92
BEGIN is a PostgreSQL language extension. There is no explicit BEGIN command in SQL92; transaction initiation is always implicit and it
terminates either with a COMMIT or ROLLBACK statement.
Note: Many relational database systems offer an autocommit feature as a convenience.
Incidentally, the BEGIN keyword is used for a different purpose in embedded SQL. You are advised to be careful about the transaction seman-
tics when porting database applications.
SQL92 also requires SERIALIZABLE to be the default transaction isolation level.
SQL - Language Statements 2002-11-22 BEGIN(7)