Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: How do I test the first char of each line in an array
Top Forums Shell Programming and Scripting How do I test the first char of each line in an array Post 302726097 by bakunin on Saturday 3rd of November 2012 02:37:25 PM
Old 11-03-2012
Quote:
Originally Posted by Marc G
I am self-learning as I can

What I need to do is test the first char of each line so I can branch out for processing.
As you say you are self-learning i won't give you a solution, but will tell you instead where you can find the solution:

See in the manual of your shell (i suppose it to be either bash or ksh - they are identical in this regard) under "Variable expansion" or "Parameter expansion". There are basically two devices:

Code:
${var#<regexp>} / ${var##<regexp>}
${var%<regexp>} / ${var%%<regexp>}

one subtracts "<regexp>" from the beginning, one from the end of the contents of "$var". You can even nest these expressions and feed the one as regexp into the other:

Code:
${var%${var#<regexp>}}

Check this out, experiment a little and eventually you will find a solution to your problem.

I hope this helps.

bakunin
 

9 More Discussions You Might Find Interesting

1. Programming

char array problem

hello i have a program in C (Unix - SOlaris5.7), and i have the next question: i have a lot of char variable, and i want store their values in a char array. The problem is what i donīt know how to put the char variable's value into the array, and i don`t know how to define the array please... (4 Replies)
Discussion started by: DebianJ
4 Replies

2. Programming

char array

hi, I have variable like, char keyword = "TRANSPARENCY "; while passing this variable to some function, first character of variable becomes null, but rest of characters still exist. Why this happens or something wrong with declaration. Their is no error while compiling & running... (2 Replies)
Discussion started by: avadhani
2 Replies

3. Programming

Passing by value a char array

Hi I am passing or want to pass value of a char array, so that even thoug the called routine is changing the values the calling function should not see the values changed, meaning only copy should be passed Here is the program #include<iostream.h> #include<string.h> void f(char a); int... (5 Replies)
Discussion started by: rkraj
5 Replies

4. UNIX for Advanced & Expert Users

test the string is char or integer

How will test the string contains numeric character or alphabet, is there any script to test ? (10 Replies)
Discussion started by: rajesh08
10 Replies

5. Programming

Array of char

I'm doing some coding in C++ Want to have a long empty string like below const char ModMisfit :: DelStr = "\r \r"; However due to the long blank the line is very long. Is there any way to avoid this and keep the... (5 Replies)
Discussion started by: kristinu
5 Replies

6. Shell Programming and Scripting

how first char in odd line and second char in even line

Hi I m having ifconfig -a o/p like sbanlab1:ksh# ifconfig -a | egrep "flags|inet" | awk -F' ' '{print $1,$2}' lo0: flags=2001000849<UP,LOOPBACK,RUNNING,MULTICAST,IPv4,VIRTUAL> inet 127.0.0.1 lo0:1: flags=2001000849<UP,LOOPBACK,RUNNING,MULTICAST,IPv4,VIRTUAL> inet 127.0.0.1 bge0:... (1 Reply)
Discussion started by: tarunn.dubeyy
1 Replies

7. Programming

help with char pointer array in C

i have an array like #define NUM 8 .... new_socket_fd = accept(socket_fd, (struct sockaddr *) &cli_addr, &client_length); char *items = {"one", "two", "three", "four", "five", "six", "seven", "eight"}; char *item_name_length = {"3", "3", "5", "4", "4", "3", "5", "5"}; ... (1 Reply)
Discussion started by: omega666
1 Replies

8. Programming

char array

cat int.c int main() { unsigned char wwn; wwn=50; wwn=00; wwn=53; wwn=30; wwn=08; wwn=09; wwn=82; wwn=17; printf("WWN: %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n ", wwn, wwn, wwn, wwn, wwn,... (8 Replies)
Discussion started by: powyama
8 Replies

9. Programming

Returning char array

I want to return a char array to the main() function, but its returning garbage value. #include<stdio.h> //#include<conio.h> #include<string.h> char* strtrmm(); int main() { char str1,c1; printf("\n Enter the string:"); gets(str1); //strtrmm(str1); printf("%s",strtrmm(str1));... (2 Replies)
Discussion started by: zinat
2 Replies

LEARN ABOUT MOJAVE

logwtmp

LOGIN(3)						   BSD Library Functions Manual 						  LOGIN(3)

NAME

     login, logout, logwtmp -- login utility functions (DEPRECATED)

SYNOPSIS

     #include <util.h>

     void
     login(struct utmp *ut);

     int
     logout(const char *line);

     void
     logwtmp(const char *line, const char *name, const char *host);

DESCRIPTION

     The login(), logout(), and logwtmp() functions are DEPRECATED; use pututxline(3) instead.

     These functions operate on the database of current users in /var/run/utmpx and the system log file.  Superuser permission is required.

     The login() function updates the /var/run/utmpx files with user information contained in ut (after converting to a struct utmpx, as described
     in pututxline(3)).

     The logout() function removes the entry from /var/run/utmpx corresponding to the device line.

     The logwtmp() function adds an entry to the system log file.  Since login() will add the appropriate entry during a login, logwtmp() is usu-
     ally used for logouts.

RETURN VALUES

     logout() returns non-zero if it was able to find and delete an entry for line, and zero if there is no entry for line in /var/run/utmpx.
     However, there is no error indication due to lack of permissions.

FILES

     /dev/*
     /var/run/utmpx

SEE ALSO

     pututxline(3), utmp(5), utmpx(5)

BSD
								 December 14, 1995							       BSD
All times are GMT -4. The time now is 11:17 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy