I am taking an intro to unix class and I can not figure out how to do part of the question. I am writing script to be exictued by a program in the tutoral.
Question:
Write every line containing the word ``delete'' produced by ``man mail'' into a file called ``delete''. Hint: What does using... (1 Reply)
i'm trying to make a script that prints the name of the script for any command line parameter, here is what i have, and get `]]' unexpected:
what am i doing wrong? (3 Replies)
Hello. I'm a complete newbie to C programming. I have a C program that wasn't written by me where I need to write some wrappers around it to automate and make it easier for a client to use. The problem is that the program accepts standard input to control the program... I'm hoping to find a simple... (6 Replies)
Hello ,
I have the folloiwing command :
sed -n "$var,$final w $destfile" $sourcefile
where :
$var - $final represent the range of line numbers to be written in $destfile
However I require this command to work in a loop for which i need the sed command to keep appending the output to the... (2 Replies)
Hi,
Please don't berate me over the simplicity of these questions. I have recently gotten into bash shell scripting and enjoy it quite a bit. One thing I have not found the answer to though is when naming a shell script, what extension is normally used (ie myscript.?)? Also where is the standard... (5 Replies)
Hello, I have a quick question that is not related to homework in any way shape or form (in case anyone wanted to know). My question is thus:
I have a file "temp" that has the two values say "5" and "3" (separated by a white space). Now, I want to simply write an if-else statement that reads... (10 Replies)
Cheers!
In /etc/syslog.conf, if an error type is not specified, is it logged anywhere (most preferable is it logged to /var/log/messages) or not?
To be more precise I am interested in error and critical level messages. At default these errors are not specified in syslog.conf, and I need to... (6 Replies)
Sorry for stupid question, but why this script gives that output?
$ awk 'BEGIN { well=56789; print 1234$well }'
1234
I expected 123456789 (9 Replies)
Discussion started by: silyin
9 Replies
LEARN ABOUT LINUX
getdelim
GETLINE(3) Linux Programmer's Manual GETLINE(3)NAME
getline, getdelim - delimited string input
SYNOPSIS
#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);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
getline(), getdelim():
Since glibc 2.10:
_POSIX_C_SOURCE >= 200809L || _XOPEN_SOURCE >= 700
Before glibc 2.10:
_GNU_SOURCE
DESCRIPTION
getline() reads an entire line from stream, storing the address of the buffer containing the text into *lineptr. The buffer is null-termi-
nated and includes the newline character, if one was found.
If *lineptr is NULL, then getline() will allocate a buffer for storing the line, which should be freed by the user program. (In this case,
the value in *n is ignored.)
Alternatively, before calling getline(), *lineptr can contain a pointer to a malloc(3)-allocated buffer *n bytes in size. If the buffer is
not large enough to hold the line, getline() resizes it with realloc(3), 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 allocated size respectively.
getdelim() works like getline(), except that a line delimiter other than newline can be specified as the delimiter argument. As with get-
line(), 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 byte. This value can be used to handle embedded null bytes in the line read.
Both functions return -1 on failure to read a line (including end-of-file condition).
ERRORS
EINVAL Bad arguments (n or lineptr is NULL, or stream is not valid).
VERSIONS
These functions are available since libc 4.6.27.
CONFORMING TO
Both getline() and getdelim() were originally GNU extensions. They were standardized in POSIX.1-2008.
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);
}
free(line);
exit(EXIT_SUCCESS);
}
SEE ALSO read(2), fgets(3), fopen(3), fread(3), gets(3), scanf(3), feature_test_macros(7)COLOPHON
This page is part of release 3.27 of the Linux man-pages project. A description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
GNU 2010-06-12 GETLINE(3)