sanjay_thakur
asked on
Delete a line in a text file using c program/perl script + system call
Hi,
I need to execute a perl script from a c program. so I presume I have to use System call. I need to pass 2 arguments to the perl script.
Arg1: filename
Arg2: string
The script should search & delete the line with the matching string.
It should return appropriate retVal back to the System code so that
the c program can check against it.
A functioning code snippet will be helpful since I am not much
fimiliar with perl.
Also is there any way to do this in C without creating a new file.
Thanks in advance for help and feedback.
I need to execute a perl script from a c program. so I presume I have to use System call. I need to pass 2 arguments to the perl script.
Arg1: filename
Arg2: string
The script should search & delete the line with the matching string.
It should return appropriate retVal back to the System code so that
the c program can check against it.
A functioning code snippet will be helpful since I am not much
fimiliar with perl.
Also is there any way to do this in C without creating a new file.
Thanks in advance for help and feedback.
int ret;
char *cmd = (char *)malloc(strlen(filename)+
sprintf(cmd,"perl -i -pe '$ret+=s/.*\\Q%s\\E.*//s;E
ret = system(cmd);
printf("%d lines deleted\n",ret>>8);
char *cmd = (char *)malloc(strlen(filename)+
sprintf(cmd,"perl -i -pe '$ret+=s/.*\\Q%s\\E.*//s;E
ret = system(cmd);
printf("%d lines deleted\n",ret>>8);
Oops, I was deleting the file not the string in the file. Go with ozo's solution.
ASKER
HI ozo,
I am getting this error
perl cmd = perl -i -pe'$ret+=s/.*\Q/etc/vmkis
Bareword found where operator expected at -e line 1, near "s/.*\Q/etc/vmkiscsi"
Backslash found where operator expected at -e line 1, near "conf\"
syntax error at -e line 1, near "s/.*\Q/etc/vmkiscsi"
Substitution pattern not terminated at -e line 1.
I am getting this error
perl cmd = perl -i -pe'$ret+=s/.*\Q/etc/vmkis
Bareword found where operator expected at -e line 1, near "s/.*\Q/etc/vmkiscsi"
Backslash found where operator expected at -e line 1, near "conf\"
syntax error at -e line 1, near "s/.*\Q/etc/vmkiscsi"
Substitution pattern not terminated at -e line 1.
sprintf(cmd,"perl -i -pe '$ret+=s#.*\\Q%s\\E.*##s;E
where # is a character not contained in string
where # is a character not contained in string
ASKER
I replaced # with Z since this is not in the string
This is what I get
perl cmd = perl -i -pe'$ret+=sZ.*\Q/etc/vmkis
Bareword found where operator expected at -e line 1, near "*\Q"
(Missing operator before Q?)
Backslash found where operator expected at -e line 1, near "conf\"
syntax error at -e line 1, near "*\Q"
syntax error at -e line 1, near "10.17.235.127:"
Execution of -e aborted due to compilation errors.
Was I not supposed to replace all the #?
This is what I get
perl cmd = perl -i -pe'$ret+=sZ.*\Q/etc/vmkis
Bareword found where operator expected at -e line 1, near "*\Q"
(Missing operator before Q?)
Backslash found where operator expected at -e line 1, near "conf\"
syntax error at -e line 1, near "*\Q"
syntax error at -e line 1, near "10.17.235.127:"
Execution of -e aborted due to compilation errors.
Was I not supposed to replace all the #?
ASKER CERTIFIED SOLUTION
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
ASKER
Thank you for your prompt help and patience and the solution.
#!/usr/bin/perl -w
$file = $ARGV[0];
$string = $ARGV[1];
open F, $file or die $!;
unlink $file if ( grep(/\Q$string/, <F>) );