awk getline will read the next input line and place it into a variable given or $0 if omitted. So in your command
Quote:
awk '{getline n; printf($0,t);next}'
you're right to supply the variable n to contain line 2, but where do you read the third line? And what does the t in the printf statement do? And, printf needs a format string which it is missing here, so it will take $0's contents for it.
Try:
as a starting point for your own refinements.
hello collegues,
I am attempting to use awk to search file1 (serverlist.csv) from each row with file2 (supported.txt). If the is no entry exists in serverlist then output to a file called notsupp.out if there is an entry output to supp.out
I can do this with basic shell scripting however... (0 Replies)
Hi,
The gcc compiler has warned about using gets(), so I've been trying my hand at getline.
Problem is that I've been able to read from a file, but what I really need is to read from a user's input.
I want to use getline like a scanf() command, but I can't figure what to substitute for the fp... (6 Replies)
I want to read a large (~1-4Gb) txt file with fields separated by "," and line separator "\n". Unfortunately, file contains \x00 (zero ASCII) symbols
AWK treats them as end of line + it ignores reminder of the line after the \x00.
As a simple example:
echo "\0060\0061\000\0060\0063" | nawk... (6 Replies)
How do you make the getline function return to the original line?
The example below should make it clear where I am currently going wrong.
Thanks
AWK SCRIPT:
-------------
awk -F '-' '{
tmpLine = "EMPTY"
print "CURRENT LINE :"$0
getline tmpLine
print "NEXT LINE :"tmpLine
}'... (1 Reply)
I am using getline to read a file in a BEGIN block:
BEGIN {
while ((getline < "testFile.html") > 0) {
print $0 > "text.html"
}
}
The file is a normal HTML file. For some reason that I have not been able to discover in the text of the file, getline never finishes and the file is... (2 Replies)
I am using awk and want to use getline from a file like below
getline x < file
However file consists of two columns and I only want to store $2
Any way I can do this?
---------- Post updated at 06:54 AM ---------- Previous update was at 06:45 AM ----------
Done something like this.... (1 Reply)
Greetings,
I have about 3000 files that I want to search. The first column in all of these 3000 files has a unique serial number on each line. The subsequent columns have lots of data.
I have another masterfile with three columns to help me find all the data I need in a moments notice:
col 1... (15 Replies)
Hi,
how do i read a file using awk for a given no of line?
e.g
1. read only first 50 line.
2. read starting from line 20 to line 60..
thanks in advance.
-alva (8 Replies)
Hi,
I have an awk script with the following function in it .
function cmd( c )
{
while( ( c | getline foo) > 0 ){
return foo ;
close( c );
}
}
c =... (4 Replies)
Howdy Folks,
It seems like it is always awk that confuses the heck out of me and I even have books and examples.
I have this line:
awk '{if (/clientIP/)(SRV = $NF); if ($2 ~ /BUNDLE-GIM/) getline; if ($2 ~ /r100595/) {print SRV,"BUNDLE-GIM",$2}}' post.txt
to parse this text:
<api... (4 Replies)
Discussion started by: port43
4 Replies
LEARN ABOUT REDHAT
getline
GETLINE(3) Linux Programmer's Manual GETLINE(3)NAME
getline, getdelim - delimited string input
SYNOPSIS
#define _GNU_SOURCE
#include <stdio.h>
ssize_t getline(char **lineptr, size_t *n, FILE *stream);
ssize_t getdelim(char **lineptr, size_t *n, int delim, FILE *stream);
DESCRIPTION
getline() reads an entire line, storing the address of the buffer containing the text into *lineptr. The buffer is null-terminated and
includes the newline character, if a newline delimiter was found.
If *lineptr is NULL, the getline() routine will allocate a buffer for containing the line, which must be freed by the user program. Alter-
natively, before calling getline(), *lineptr can contain a pointer to a malloc()-allocated buffer *n bytes in size. If the buffer is not
large enough to hold the line read in, getline() resizes the buffer to fit with realloc(), updating *lineptr and *n as necessary. In either
case, on a successful call, *lineptr and *n will be updated to reflect the buffer address and size respectively.
getdelim() works like getline(), except a line delimiter other than newline can be specified as the delimiter argument. As with getline(),
a delimiter character is not added if one was not present in the input before end of file was reached.
RETURN VALUE
On success, getline() and getdelim() return the number of characters read, including the delimiter character, but not including the termi-
nating null character. This value can be used to handle embedded null characters in the line read.
Both functions return -1 on failure to read a line (including end of file condition).
ERRORS
EINVAL Bad parameters (n or lineptr is NULL, or stream is not valid).
EXAMPLE
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
int main(void)
{
FILE * fp;
char * line = NULL;
size_t len = 0;
ssize_t read;
fp = fopen("/etc/motd", "r");
if (fp == NULL)
exit(EXIT_FAILURE);
while ((read = getline(&line, &len, fp)) != -1) {
printf("Retrieved line of length %zu :
", read);
printf("%s", line);
}
if (line)
free(line);
return EXIT_SUCCESS;
}
CONFORMING TO
Both getline() and getdelim() are GNU extensions. They are available since libc 4.6.27.
SEE ALSO read(2), fopen(3), fread(3), gets(3), fgets(3), scanf(3)GNU 2001-10-07 GETLINE(3)