Hi all you enlightened unix people,
I've been trying to execute a perl script that contains the following line within backticks:
`grep -f patternfile.txt otherfile.txt`;It takes normally 2 minutes to execute this command from the bash shell by hand.
I noticed that when i run this command... (2 Replies)
Hi,
A datafile containing lines such as below needs to be split:
500000000000932491683600000000000000000000000000016800000GS0000000000932491683600*HOME
I need to get the 2-5, 11-20, and 35-40 characters and I can do it via cut command.
cut -c 2-5 file > temp1.txt
cut -c 11-20 file >... (9 Replies)
I'm sorting files from a source directory by size into 4 categories then copying them into 4 corresponding folders, just wondering if there's a faster/better/more_elegant way to do this:
find /home/user/sourcefiles -type f -size -400000k -exec /bin/cp -uv {} /home/user/medfiles/ \;
find... (0 Replies)
we have 30 GB files on our filesystem which we need to copy daily to 25 location on the same machine (but different filesystem).
cp is taking 20 min to do the copy and we have 5 different thread doing the copy.
so in all its taking around 2 hr and we need to reduce it.
Is there any... (9 Replies)
Hi,
I have a script below for extracting xml from a file.
for i in *.txt
do
echo $i
awk '/<.*/ , /.*<\/.*>/' "$i" | tr -d '\n'
echo -ne '\n'
done
.
I read about using multi threading to speed up the script.
I do not know much about it but read it on this forum.
Is it a... (21 Replies)
awk "/May 23, 2012 /,0" /var/tmp/datafile
the above command pulls out information in the datafile. the information it pulls is from the date specified to the end of the file.
now, how can i make this faster if the datafile is huge? even if it wasn't huge, i feel there's a better/faster way to... (8 Replies)
Hello guys,
I'm cleaning out big XML files (we're talking about 1GB at least), most of them contain words written in a non-latin alphabet.
The command I'm using is so slow it's not even funny:
cat $1 | sed -e :a -e 's/<*>//g;/</N;//ba;s/</ /g;s/>/... (4 Replies)
Hi,
I have a large number of input files with two columns of numbers.
For example:
83 1453
99 3255
99 8482
99 7372
83 175
I only wish to retain lines where the numbers fullfil two requirements. E.g:
=83
1000<=<=2000
To do this I use the following... (10 Replies)
Good evening
Im new at unix shell scripting and im planning to script a shell that removes headers for about 120 files in a directory and each file contains about 200000
lines in average.
i know i will loop files to process each one and ive found in this great forum different solutions... (5 Replies)
I have the below command which is referring a large file and it is taking 3 hours to run. Can something be done to make this command faster.
awk -F ',' '{OFS=","}{ if ($13 == "9999") print $1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11,$12 }' ${NLAP_TEMP}/hist1.out|sort -T ${NLAP_TEMP} |uniq>... (13 Replies)
Discussion started by: Peu Mukherjee
13 Replies
LEARN ABOUT REDHAT
getpwent
GETPWENT(3) Linux Programmer's Manual GETPWENT(3)NAME
getpwent, setpwent, endpwent - get password file entry
SYNOPSIS
#include <pwd.h>
#include <sys/types.h>
struct passwd *getpwent(void);
void setpwent(void);
void endpwent(void);
DESCRIPTION
The getpwent() function returns a pointer to a structure containing the broken out fields of a line from /etc/passwd. The first time it is
called it returns the first entry; thereafter, it returns successive entries.
The setpwent() function rewinds the file pointer to the beginning of the /etc/passwd file.
The endpwent() function closes the /etc/passwd file.
The passwd structure is defined in <pwd.h> as follows:
struct passwd {
char *pw_name; /* user name */
char *pw_passwd; /* user password */
uid_t pw_uid; /* user id */
gid_t pw_gid; /* group id */
char *pw_gecos; /* real name */
char *pw_dir; /* home directory */
char *pw_shell; /* shell program */
};
RETURN VALUE
The getpwent() function returns the passwd structure, or NULL if there are no more entries or an error occurs.
ERRORS
ENOMEM Insufficient memory to allocate passwd structure.
FILES
/etc/passwd
password database file
CONFORMING TO
SVID 3, BSD 4.3
SEE ALSO fgetpwent(3), getpwnam(3), getpwuid(3), getpw(3), putpwent(3), passwd(5)GNU 1996-05-27 GETPWENT(3)