how to remove lines containing 'abc' in a text file?

[Umesh]

Please help. THANKS.

 

[jacob navia]

Please help. THANKS.

Do your own homework. We do not support cheaters

 

[Keith Thompson]

Please help. THANKS.

No.

 

[pete]

Please help. THANKS.

/* BEGIN abc_remove.c */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>

#define STRING "abc"
#define ARGV_0 "abc_remove"
#define INITIAL_BUFFER_SIZE 0

struct list_node {
struct list_node *next;
void *data;
};

int get_line(char **lineptr, size_t *n, FILE *stream);
struct list_node *string_node(struct list_node **head,
struct list_node *tail,
char *string);
void list_free(struct list_node *node, void (*free_data)(void *));
int list_fputs(struct list_node *node, FILE *stream);

int main(int argc, char *argv[])
{
FILE *fp;
struct list_node *head, *tail;
int rc;
char *buff;
size_t size;

if (argc > 1) {
size = INITIAL_BUFFER_SIZE;
buff = malloc(size);
if (buff == NULL) {
size = 0;
}
while (*++argv != NULL) {
fp = fopen(*argv, "r");
if (fp == NULL) {
printf("\nfopen() problem with \"%s\"\n", *argv);
free(buff);
exit(EXIT_FAILURE);
}
printf("\n%s open for reading.\n", *argv);
tail = head = NULL;
while ((rc = get_line(&buff, &size, fp)) > 0) {
if (strstr(buff, STRING) == NULL) {
tail = string_node(&head, tail, buff);
if (tail == NULL) {
puts("Node allocation failure.");
free(buff);
fclose(fp);
exit(EXIT_FAILURE);
}
}
}
if (rc == 0) {
puts("realloc returned a null pointer value");
free(buff);
fclose(fp);
exit(EXIT_FAILURE);
}
fclose(fp);
printf("%s closed.\n", *argv);
fp = fopen(*argv, "w");
if (fp == NULL) {
printf("\nfopen() problem with \"%s\"\n", *argv);
free(buff);
exit(EXIT_FAILURE);
}
printf("%s open for writing.\n", *argv);
list_fputs(head, fp);
fclose(fp);
printf("%s closed.\n", *argv);
list_free(head, free);
}
free(buff);
} else {
puts("This program removes all lines\n"
"containing the string \"" STRING "\", "
"from text files"
"\n\nUsage:\\" ARGV_0
" <FILE_1.txt> <FILE_2.txt> ...");
}
return 0;
}

int get_line(char **lineptr, size_t *n, FILE *stream)
{
int rc;
void *p;
size_t count;

count = 0;
while ((rc = getc(stream)) != EOF) {
if (count != -1) {
++count;
}
if (count + 2 > *n) {
p = realloc(*lineptr, count + 2);
if (p == NULL) {
if (*n > count) {
if (rc != '\n') {
(*lineptr)[count] = '\0';
(*lineptr)[count - 1] = (char)rc;
} else {
(*lineptr)[count - 1] = '\0';
}
} else {
if (*n != 0) {
**lineptr = '\0';
}
ungetc(rc, stream);
}
count = 0;
break;
}
*lineptr = p;
*n = count + 2;
}
if (rc == '\n') {
(*lineptr)[count - 1] = '\0';
break;
}
(*lineptr)[count - 1] = (char)rc;
}
if (rc != EOF) {
rc = count > INT_MAX ? INT_MAX : count;
} else {
if (*n > count) {
(*lineptr)[count] = '\0';
}
}
return rc;
}

struct list_node *string_node(struct list_node **head,
struct list_node *tail,
char *string)
{
struct list_node *node;

node = malloc(sizeof *node);
if (node != NULL) {
node -> next = NULL;
node -> data = malloc(strlen(string) + 1);
if (node -> data != NULL) {
if (*head == NULL) {
*head = node;
} else {
tail -> next = node;
}
strcpy(node -> data, string);
} else {
free(node);
node = NULL;
}
}
return node;
}

void list_free(struct list_node *node, void (*free_data)(void *))
{
struct list_node *next_node;

while (node != NULL) {
next_node = node -> next;
free_data(node -> data);
free(node);
node = next_node;
}
}

int list_fputs(struct list_node *node, FILE *stream)
{
while (node != NULL) {
if (fputs(node -> data, stream) == EOF) {
return EOF;
}
if (putc('\n', stream) == EOF) {
return EOF;
}
node = node -> next;
}
return '\n';
}

/* END abc_remove.c */

 

[borkhuis]

Please help. THANKS.

[OT-answer, for more information go to comp.editors]
Open the file in vi, and execute the following command:
:g/abc/d

[Another OT-asnwer, for more information on this go to comp.unix]
Execute the following:

grep -v abc <filename>

For the implementation in C, please take a look at the sourcecode for
grep.

Hope this helps [NOT]

Kind regards,
Johan

 

[Guru Jois]

Please help. THANKS.

[OT-answer, for more information go to comp.editors]
Open the file in vi, and execute the following command:
:g/abc/d

[Another OT-asnwer, for more information on this go to comp.unix]
Execute the following:

grep -v abc <filename>

For the implementation in C, please take a look at the sourcecode for
grep.

Hope this helps [NOT]

Kind regards,
Johan

continuation...
There is no command that alters the content of file in Unix except one
or two such as dos2unix etc. So filtering is to be done..

grep -v abc filenale > temp.txt // store all lines that doesn't
contain abc in temp file
mv temp.txt filename // move temp file to source file.

Bye
Guru Jois

 

[Charlton Wilbur]

U> Please help. THANKS.

Step 1: Implement perl.

Step 2: perl -ni -e 'print if /abc/;' filename

Good luck!

Charlton

 

[Walter Roberson]

U> Please help. THANKS.

Step 1: Implement perl.

Step 2: perl -ni -e 'print if /abc/;' filename

Arguably, that would "select" lines containing 'abc' rather than
"remove lines containing 'abc'". There is a meaning of "remove"
congruous with "select and place elsewhere", but that meaning
of "remove" would normally be signalled with the preposition "to"
rather than "in" -- "remove to <a location>" rather than
"remove in <something>".

 

[Charlton Wilbur]

U> Please help. THANKS.

WR> Arguably, that would "select" lines containing 'abc' rather
WR> than "remove lines containing 'abc'". There is a meaning of
WR> "remove" congruous with "select and place elsewhere", but that
WR> meaning of "remove" would normally be signalled with the
WR> preposition "to" rather than "in" -- "remove to <a location>"
WR> rather than "remove in <something>".

Whoops, you're right.

s/if/unless/ in what I wrote.

Charlton